1546 PDF
1546 PDF
1546 PDF
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Amendment Record
Contents
Amendment Record 1
List of Effective Pages 1
Contents 1
Explanatory Note 1
Revision History 1
Foreword 1
Purpose and Scope 1
Manual of Air Traffic Services Part 1 – Status 1
Interpretation of Words 1
Collective Words 2
Manual of Air Traffic Services Part 1 – Format 2
Headings 2
References 2
Appendices 2
Gender 2
Page Numbering 2
Manual of Air Traffic Services Part 1 – Amendments 3
Amendments 3
Effective Date 3
Supplementary Instructions 3
ATS forms 3
Copyright 3
Enquiries 4
Units of Measurement and Conversion Tables 1
Units 1
Conversion Tables 2
Section 1: Chapter 1 1
Section 1: Chapter 2 1
Flight Rules 1
1. Division of Airspace 1
2. Classification of Airspace 1
3. Speed Limit 3
4. Visual Flight Rules 4
5. Instrument Flight Rules 7
6. Aerodrome Traffic Zone (ATZ) 8
7. Cancellation of IFR Flight 8
8. Special VFR Flight 8
9. Class C Airspace 11
10. Filing of Flight Plans 12
11. Non-Standard Routes 14
12. Repetitive Flight Plan 14
13. Availability of Supplementary Flight Plan Information 14
14. Booking-Out 14
15. Exemptions and Non-Standard Flights 14
16. Aircraft Proximity (AIRPROX) 14
17. Search Action 15
18. Failure of Navigation Lights 16
19. Operations of Aircraft with Unserviceable Equipment 16
20. Action When Captive Balloons Break Free 16
21. Radio Mandatory Zones 16
Section 1: Chapter 3 1
Separation Standards 1
1. Provision of Standard Separation 1
2. Increased Separation 1
3. Reduced Separation 1
4. Essential Traffic Information 2
5. Vertical Separation 2
6. Horizontal Separation 4
7. Lateral Separation 5
8. Longitudinal Separation – Time and Distance 7
9. Wake Turbulence Separation Requirements 11
10. Separation Based on ATS Surveillance System Information 17
Section 1: Chapter 4 1
Control of Traffic 1
1. Air Traffic Control Clearances 1
2. Contents of Clearances 1
3. Clearance Limit 2
4. Conditional Clearances 2
5. Route 3
6. Allocation of Cruising Levels 3
7. Amendments to Clearances 5
8. Withholding Clearance 5
9. Data Display 6
10. Flight Priorities 6
11. Notification of Flights 8
12. Transfer of Control 9
13. Expected Approach Time (EAT) 10
14. Calculated Take Off Time (CTOT) 10
15. Formation Procedures 11
16. Ground Proximity Warning System 13
17. Non-Deviating Status (NDS) 14
18. Unusual Aerial Activity 14
19. Balloon Flights in Controlled Airspace 14
20. Glider Operations in Controlled Airspace 15
21. Police Flights 16
22. Helicopter Emergency Medical Service (HEMS) 17
23. Mareva Injunctions 17
Section 1: Chapter 5 1
Section 1: Chapter 6 1
Section 1: Chapter 7 1
Section 1: Chapter 8 1
Diversion Procedures 1
1. Introduction 1
2. Diversions Originated by the Pilot 1
3. Diversions Originated by the Ground Organisation 2
4. Action by Pilot 2
5. Diversion of Military Aircraft 2
6. Diversion to RAF Aerodromes 2
Section 1: Chapter 9 1
Royal Flights 1
1. Introduction 1
2. Procedures for Royal Flights in Fixed-wing Aircraft 1
3. Royal Flight Callsigns 3
4. Diversions 3
5. Incidents Involving Royal Flights 3
Section 1: Chapter 10 1
Section 1: Chapter 11 1
Section 1: Chapter 12 5
Section 1: Chapter 13 1
Speed Control 1
1. General 1
2. Arrivals and Descending Aircraft 1
3. Departing Aircraft 2
4. Speed Control Phraseology and Additional Guidance 2
Section 2: Chapter 1 3
Aerodrome Control 3
1. Provision of Services 3
2. Responsibilities 3
3. Co-ordination 4
4. Transfer of Control 5
5. Airspace Classification 5
6. Effect of Weather on Operations 5
7. Information to Aircraft 6
8. Essential Aerodrome Information 7
9. Grass Aerodromes 8
10. Control of Surface Traffic 8
11. Taxiing Aircraft 12
12. Clearance Limit 13
13. Awaiting Take-off 14
14. Line-Up Clearance 14
15. Take-off Clearance 15
16. Cancelling Take-off Clearance 16
17. Designated Positions in the Traffic Circuit 18
18. Arriving Aircraft 18
19. Landing 19
20. Exemptions from Separation Minima in the Traffic Circuit 20
21. Aerodrome Traffic Monitor (ATM) 20
22. Low Approach Restrictions 21
23. Landing Direction and Runway-in-use 21
24. Runway Changes 22
25. Closure or Restricted Operation of Aerodromes 22
26. Extensions of Watch 24
27. Availability of Aerodromes for Special Flights 24
28. Work on the Manoeuvring Area 24
29. Ground Signals and Markings 24
30. Inspection of Runways 24
31. Aerodrome Fire Service 25
32. Release of Racing Pigeons 26
Section 2: Chapter 2 1
Section 2: Chapter 3 1
4. Storage 1
5. Lasers, Searchlight and Fireworks Displays 1
Section 2: Chapter 4 1
Windshear 1
1. Introduction 1
2. Conditions Conducive to Windshear 1
3. Effects of Windshear 1
4. Windshear Detection Systems 3
5. ATC Action 4
6. ATIS Broadcasts 4
Section 2: Chapter 5 1
Prevailing Visibility 1
1. Introduction 1
2. Reporting of Prevailing Visibility 1
3. Effect on ATC Procedures 1
Section 2: Chapter 6 1
Aerodrome Inspections 1
1. Introduction 1
2. Aerodrome Surface Inspections 1
3. Snow and Ice Conditions 2
4. Aerodrome Lighting Inspections 3
5. Reporting Action 3
Section 2: Chapter 7 1
Wet Runways 1
1. Introduction 1
2. Reporting Wet Runways 1
3. Unofficial Observations 2
4. Calibrated Runways 2
5. Runway Drainage System 2
Section 2: Chapter 8 1
Section 3: Chapter 1 3
Approach Control 3
1. Provision of Services 3
2. Information to Aircraft 4
3. Information to Other Units 5
4. Co-ordination 6
5. Transfer of Control 7
6. Delegation 7
7. Transfer of Communication 8
8. VFR Flights 8
9. Arriving Aircraft 10
10. Transmission of Meteorological Information 13
11. ATIS 14
12. Visual Approach 14
13. Instrument Approaches 15
14. Holding Procedures 16
15. Approach Sequence 16
16. Expected Approach Time 17
17. Holding for Weather Improvement 17
18. Diversions 18
19. Aerodromes Receiving Diversions 18
20. Departing Aircraft 19
21. Joining and Overflying Aircraft 20
Section 3: Chapter 2 1
Approach Radar 1
1. Area of Responsibility 1
2. Services 1
3. Co-ordination 1
4. Control of Inbound Aircraft 2
5. Inbound Aircraft – Provision of Weather Information 2
6. Altimeter Setting 2
7. Obstacle Clearance Criteria 2
8. Position Information 2
9. Vectoring to Final Approach 2
10. Clearance to Land 6
11. Surveillance Radar Approaches 7
12. SRA Terminating at 2 Miles 7
13. SRA Terminating at Less Than 2 Miles 7
14. Glidepath and Advisory Height 8
15. Missed Approach Instructions 8
16. Discontinuing of Radar Approach 9
17. Departures 9
Section 3: Chapter 3 1
Section 4: Chapter 1 1
Section 4: Chapter 2 1
Section 4: Chapter 3 1
Section 4: Chapter 4 2
Section 4: Chapter 5 1
Meteorological Information 1
1. Supply of Information 1
2. Summary of Meteorological Information Supplied to ACCs 1
3. Transmission to Aircraft 1
Section 4: Chapter 6 3
Section 5: Chapter 1 1
Aircraft Emergencies 1
1. Introduction 1
2. Controllers Responsibility 2
3. Recognising an Emergency Situation 2
4. Distress and Urgency Messages 3
5. Indications by Visual Signal from Aircraft 4
6. Indications on the Situation Display 4
7. Emergency Triangle Procedure 5
8. Emergency Aircraft – Selection of Controlling Agency 5
9. Distress and Diversion Cell 6
10. Intercepted Messages 7
11. Aircraft Emergencies – General Principles 8
12. RAF Distress and Diversion 12
13. Fuel Jettisoning 12
14. Emergency Overweight Landings 13
15. Facilitation 13
16. Ballistic Recovery Systems 14
Section 5: Chapter 2 1
Section 5: Chapter 3 1
Overdue Aircraft 1
1. Introduction 1
2. Aerodrome Procedure 1
3. ACC Procedures 3
Section 5: Chapter 4 1
Radio Failure 1
1. Introduction 1
2. Standard Procedure for Controllers 1
3. Use of ATS Surveillance Systems 2
4. Failure of Two-way Radio Communications 3
5. VMC Procedures for Pilots 3
6. IMC Procedures for Pilots 4
7. Resumption of Normal Operations 6
Section 5: Chapter 5 1
Section 5: Chapter 6 1
Alerting Service 1
1. Introduction 1
2. Aerodromes 1
3. Area Control Centres 1
4. Civil Rescue Organisations 3
5. Aeronautical Rescue Co-ordination Centre 3
6. Rescue Craft – Callsign 3
7. Phases of Emergency 4
8. Telephone Precedence 6
9. Telephone Message 6
10. Operations normal 7
Section 5: Chapter 7 1
Section 5: Chapter 8 1
Miscellaneous Procedures 1
1. Emergency Position Indicating Radio Beacons 1
2. Ships in Distress 1
3. Nuclear and Chemical Accidents 1
Section 5: Chapter 9 1
Section 6: Chapter 1 1
General Guidance 1
1. Introduction 1
2. Reports by Telephone 2
3. Reports 2
4. ATS Records 2
5. Access to Original Records 3
5A. Accidents 3
5B. Incidents (including AIRPROX) 3
6. Disclosure of Information 3
7. Additional AAIB Post-Incident Investigation 4
Section 6: Chapter 2 1
Section 6: Chapter 3 1
Section 6: Chapter 4 1
Infringement of Legislation 1
1. Introduction 1
2. Tracing Action 1
3. Written Reports 2
4. Forwarding Reports 2
5. Military Aircraft 2
Section 6: Chapter 5 1
Miscellaneous Reports 1
1. Bird Strikes 1
2. Maritime Incidents 1
3. Unidentified Flying Objects 2
4. Sonic Boom 3
5. Malicious Interference to VHF Communications 4
Section 7: Chapter 1 1
Meteorological Services 1
1. Briefing of Controllers 1
2. Explanation of Terms 1
3. Supply of Information 1
4. Aerodrome Meteorological Reports (Routine) 3
5. Aerodrome Meteorological Reports (Special) 5
6. Coded Aerodrome Weather Reports 6
7. SIGMET 6
8. Forecasts 7
9. Aerodrome Warnings 8
10. Provision and Exchange of Information Relevant to Volcanic Ash 9
Section 7: Chapter 2 1
Telecommunications Services 1
1. The Aeronautical Mobile Service 1
2. Air-Ground Communications and Surveillance Systems 1
3. Aeronautical Fixed Service 2
4. Serviceability of Equipment 2
5. Aircraft Radio Equipment Fault Reports 3
6. Withdrawal of Approach Aids 3
Section 7: Chapter 3 1
Section 8: Chapter 1 1
8. Clocks 3
9. Publications 3
10. ATC Watch Log 4
11. Aircraft Movement Log 5
12. Impounding of ATC Watch Logs 5
13. Disposal of Records 5
Appendix A 1
Appendix B 1
Appendix C 1
Appendix D 1
Appendix E 1
Attachment to Appendix E 1
Appendix F 1
Appendix G 1
Appendix H 1
Directory 1
Appendix I 1
Appendix J 1
Index 1
Index 1
Explanatory Note
Edition 7 comprises:
Editorial changes
Classification of Airspace
Section 1, Chapter 2, Paragraph 2.1, Table 1, Note 4: Text clarified
Wake Turbulence
Section 1, Chapter 3, Paragraph 9D.1: Text amended to include reference to MATS Part 2
Section 1, Chapter 3, Paragraph 9F.2: Text amended to include reference to MATS Part 2
Unknown Traffic
Section 1, Chapter 6, Paragraph 15.2, Table 5: Reference to SVFR flight removed from Class A
airspace.
Revision History
The table below is provided as a reference to highlight when major changes were made to the
content of the MATS Part 1. It does not cover editorial changes.
As necessary, an update will be added to the table at each amendment and the detailed
Explanatory Note will continue to be provided. Pages that are affected will be listed for each
revision in the explanatory notes.
Seventh Edition
Subject Origin
Removal of Definitions and Abbreviations (see CAP 1430 – UK ATM Vocabulary) CAA
Foreword
(2) MATS Part 2 Instructions that apply to a particular ATSU, produced locally and
approved by the CAA. They amplify and interpret, at local level, MATS Part 1
instructions. Any authorisation required by MATS Part 1 is to appear in the MATS
Part 2.
3. Definitions and abbreviations are contained within CAP 1430 – UK Air Traffic
Management Vocabulary.
Interpretation of Words
5. To avoid any misunderstanding within the MATS, certain words are to be interpreted as
having specific meanings when they are the operative words in an instruction.
Collective Words
6. To prevent excessive repetition in instructions, certain collective words have been
adopted.
Headings
7. Main subject headings are numbered. Where subjects have been expanded or qualified,
bold headings have been inserted to break up the text. All the text under the main subject
headings, including the material under the bold headings, belongs to that main subject
heading.
References
8. All references in the index are to the section, chapter (if applicable) and page number as
shown at the foot of each page. References to other documents, such as the ANO, are as
at the effective date of the page. The current status of all CAA publications can be verified
on the CAA website.
Appendices
9. Each appendix (or in some cases part of an appendix) is in suitable form for removal and
independent use.
Gender
10. In the interests of simplicity, any reference to the masculine gender can be taken to mean
either male or female.
Page Numbering
11. The List of Effective Pages is numbered at the foot using roman numerals. The
Explanatory Note, Foreword and Glossary are numbered at the foot with Arabic page
numbers, and Sections 1 to 8 are numbered at the foot with the Section, Chapter and
Page numbers. Supplementary Instructions have an identifying number and year of issue
with individual page number; and Appendices have the word Appendix followed by an
identifying letter an individual page number.
Amendments
12. Amendments to MATS Part 1 will be published in March, July and November.
13. Underlining is used to indicate new or revised text. Two weeks prior to the effective date
of an amendment, the full CAP 493 will be available on the CAA website (www.caa.co.uk).
This document will contain a summary of changes and an updated List of Effective Pages.
From the effective date of the amendment the superseded version of CAP 493 will be
removed from the website.
14. Printed copies of CAP 493, together with amendments, are available for purchase from
the CAA’s publishers, whose details are given on the inside cover of this publication.
Effective Date
15. The effective date of an instruction is stated at the foot of the page. Publication of a new
edition means that all pages will have the same date; however, new instructions are
effective on the amendment publication date.
Supplementary Instructions
16. Supplementary Instructions to MATS Part 1 are issued for the following reasons:
17. Supplementary Instructions will be incorporated into the main body of the document in a
suitable and timely manner.
ATS forms
18. The CAA no longer prints ATS forms in bulk. All CAA forms may be downloaded from the
CAA website and reproduced locally. The following link should be used to access ATS
forms on the internet: www.caa.co.uk/atsforms
19. In the event of difficulty accessing any forms from the CAA website, printed examples are
available on request from the CAA.
Copyright
20. The copyright details of this publication are printed on the inside cover.
Enquiries
21. Any enquiries about the content of the MATS Part 1 should be addressed to:
RH6 0YR
E-mail: ats.enquiries@caa.co.uk
Units
The units of measurement to be used by controllers in communication with aircraft are listed in the
table below:
Measurement of Units
Distance used in navigation, position reporting, etc; Nautical miles and tenths but spoken as
generally in excess of 2 to 3 nautical miles ‘miles’
Distance from cloud Metres
Relatively short distances such as those relating to Metres
aerodromes (e.g. runway lengths, distances of
obstructions from runway or of facilities from the
aerodrome where accuracy of greater than one tenth of
a nautical mile is required)
Radar-position reporting and ranges from touchdown Nautical miles and/or fractions thereof
but spoken as ‘miles’
Radar-azimuth displacement from final approach track Metres
Altitudes elevations and heights Feet
Depths of snow and slush Centimetres or millimetres
Horizontal speed including wind speed Knots
Vertical speed Feet per minute
Wind direction for landing and take-off Degrees Magnetic
Wind direction except for landing and taking off Degrees True
Visibility (including flight visibility) Kilometres and Metres
Runway visual range Metres
Altimeter setting Hectopascals
Temperature Degrees Celsius
Weight Metric tons or Kilogrammes
Time Hours and minutes, the day of 24 hours
beginning at midnight UTC
Conversion Tables
Tables for converting values from one unit to another appear below.
Feet / Statute
Metres Feet NM Km
Metres Miles
0.305 1 3.281 0.87 1 1.61
0.061 2 6.562 1.74 2 3.22
0.914 3 9.842 2.61 3 4.83
1.219 4 13.123 3.47 4 6.44
1.524 5 16.404 4.34 5 8.05
1.829 6 19.685 5.21 6 9.66
2.134 7 22.966 6.08 7 11.27
2.438 8 26.247 6.95 8 12.88
2.743 9 29.528 7.82 9 14.49
3.048 10 32.809 8.68 10 16.09
6.096 20 65.617
9.144 30 98.426
12.192 40 131.234 Statue Miles / Nautical Miles /
15.24 50 164.043 Kilometres
18.29 60 196.852
SM NM Km
21.34 70 229.66
24.38 80 262.469 1.15 1 1.85
27.43 90 295.278 2.30 2 3.7
30.48 100 328.087 3.45 3 5.56
60.96 200 656.1 4.61 4 7.41
91.44 300 984.3 5.76 5 9.26
121.92 400 1,312.3 6.91 6 11.11
152.4 500 1,640.4 8.06 7 12.96
304.8 1,000 3,280.9 9.21 8 14.82
609.6 2,000 6,561.7 10.36 9 16.67
914.4 3,000 9,842.6 11.52 10 18.52
1,219.2 4,000 13,123.5
1,524.0 5,000 16,404.3
Lb / Kg / Lb
Kg Lb / Kg Lb
0.454 1 2.205
0.907 2 4.409
1.361 3 6.614
1.814 4 8.818
2.268 5 11.023
2.722 6 13.228
3.175 7 15.432
3.629 8 17.637
4.082 9 19.842
4.536 10 22.046
9.072 20 44.092
13.608 30 66.139
18.144 40 88.185
22.680 50 110.231
1,000 Kg = 1 metric ton
SECTION 1: CHAPTER 1
1. Introduction
1.1 Air Traffic Services within the UK are provided in accordance with the Air Navigation
Order, Rules of the Air Regulations and Standardised European Rules of the Air.
Generally these are in line with the Standards and Recommended Practices of the
International Civil Aviation Organisation.
1.2 The Manual of Air Traffic Services contains instructions and guidance for controllers
providing Air Traffic Services to cater for both routine and many emergency situations.
However, nothing in this manual prevents controllers from using their own discretion and
initiative in response to unusual circumstances, which may not be covered by the
procedures herein.
2. Language Requirement
2.1 In accordance with ICAO requirements the English language shall be used for all
operational communications at ATSUs within the UK.
2.2 Operational communication between UK and non-UK ATSUs shall, on the part of the UK
ANSP, be conducted in the English language.
2.3 ANSPs may designate, within their unit, operational areas in which all communications
(operational and non-operational) shall be in the English language.
(2) prevent collisions between aircraft on the manoeuvring area and obstructions on
that area;
(4) provide advice and information useful for the safe and efficient conduct of flights;
(5) notify appropriate organisations regarding aircraft in need of search and rescue aid,
and assist such organisations as required.
Note 1: These provisions are general statements which represent high-level safety objectives to
be met when providing ATS. (GM1 SERA.7001)
Note 2: ATS personnel are not solely responsible for the prevention of collisions. Pilots and
vehicle drivers must also fulfil their own responsibilities in accordance with Rules of the
Air.
Note 3: Compliance with the procedures contained in this Manual and supplemented in MATS
Part 2 are considered to meet the above objectives.
4.2 EASA regulations require that ATS units, in carrying out their objectives, shall have ‘due
regard’ for the requirements of the aircraft operators consequent on their obligations as
specified in the relevant EASA legislation on Air Operations, and, if so required by the
aircraft operators, shall make available to them or their designated representatives such
information as may be available to enable them or their designated representatives to
carry out their responsibilities ((EU) 923/2012 SERA.7005 (a)).
Note: The expression ‘due regard’ is meant to indicate that the ATS units, in their co-ordination
with the aircraft operators, should take into account the obligations of the operators
specified in the EASA rules on air operations, and provide them with the information they
require to operate in accordance with those rules (GM1 SERA.7005(a)).
4.3 When so requested by an aircraft operator, messages (including position reports) received
by air traffic services units and relating to the operation of the aircraft for which operational
control service is provided by that aircraft operator shall, so far as practicable, be made
available immediately to the aircraft operator or a designated representative in
accordance with locally agreed procedures ((EU) 923/2012 SERA.7005 (b)).
Note 2: Operational control service refers to the aircraft operator’s responsibility for exercising
authority over the initiation, continuation, diversion or termination of a flight in the interest
of safety of the aircraft and the regularity and efficiency of the flight.
5.2 An Air Traffic Control Service shall include the provision of pertinent flight information.
(1) weather;
7.2 In Class G airspace, the ICAO requirements for Flight Information Service are met through
a suite of services, known as the ‘UK Flight Information Services’ as detailed in Section 1
Chapter 12. The UK Flight Information Services consist of:
8. Alerting Service
8.1 An Alerting Service is provided to notify appropriate organisations regarding aircraft in
need of SAR aid and assist such organisations as required.
9.2 All ATC units shall provide an Alerting Service to aircraft under their jurisdiction.
Note: The term ‘ATSU’ will be used when it is significant that the instruction applies to an AFIS
unit in addition to an ATC unit.
10.2 Where controllers are working together they should, whenever possible, pay attention to
each other’s actions in order to provide an additional safeguard against errors or
omissions.
SECTION 1: CHAPTER 2
Flight Rules
1. Division of Airspace
1.1 UK airspace is divided into two Flight Information Regions. Within each region the
airspace below FL245 is known as the lower FIR and that at and above as the Upper
Flight Information Region (UIR).
2. Classification of Airspace
2.1 The classification of the airspace within an FIR determines the flight rules which apply and
the minimum services that are to be provided (SERA.6001). These are summarised
below.
Flight
Class Aircraft Requirements Minimum Services by ATC Unit
Rules
IFR
ATC clearance before entry.
B and Separate all aircraft from each other.
Comply with ATC instructions.
VFR
Flight
Class Aircraft Requirements Minimum Services by ATC Unit
Rules
(a) Separate IFR flights from other IFR
flights;
IFR (b) Pass traffic information to IFR flights and
ATC clearance before entry. SVFR flights on VFR flights and give
D and
Comply with ATC instructions. traffic avoidance advice when requested;
VFR
(c) Pass traffic information to VFR flights on
all other flights and provide traffic
avoidance advice when requested.
VFR VFR flights do not require (c) Pass traffic information, as far as
clearance. practicable, to participating VFR flights in
accordance with the type of UK FIS
provided.
IFR
Participating IFR flights are
Separation provided, as far as practicable,
F and expected to comply with ATC
between participating IFR flights.
instructions.
VFR
IFR
VFR
Note 1: Class B airspace is considered less restrictive than Class A airspace; Class C airspace
less restrictive than Class B airspace, etc. (GM1 SERA.6001(a))
Note 4: When providing traffic avoiding advice in Class D airspace, controllers shall remind pilots
of their responsibility to remain clear of cloud with the surface in sight.
Note 5: When the controller considers that more immediate action is required by the pilot, traffic
avoidance advice may be passed by ATC before traffic information.
3. Speed Limit
3.1 Airspace speed limits and procedure speed limits are two types of speed restrictions,
which may apply to certain flights.
(3) for exempted VFR flights in Class C airspace when authorised by an ATC unit in
accordance with MATS Part 2;
(4) for exempted flights in Class D airspace when authorised by an ATC unit in
accordance with MATS Part 2;
(6) aircraft taking part in flying displays when authorised by the CAA;
Note: Aircraft type and Aircraft Operator combinations exempt from the Class D airspace speed
restriction are published in the UK AIP according to the aerodrome to which they apply.
3A.3 Controllers may only exercise the authority granted in paragraph 3A.2 (3) above when
they are satisfied that they are in contact with all aircraft in the relevant part of the
airspace. VFR flights in the vicinity are to be warned about aircraft flying at a higher
speed.
3A.4 An airspace speed limit must not be relaxed by ATC for flights which will be transiting from
a known traffic environment, e.g. Class A airspace, into airspace where the ‘see and
avoid’ principle operates as the primary means of separation.
3A.5 In Class E, F and G airspace, conflicting traffic may not be known to ATC and so it is
necessary for all flights to make use of the ‘see and avoid’ principle. In order for this to
operate effectively, controllers shall not authorise a relaxation of the airspace speed limit.
Note: The speed limitation of 250 kt for VFR flights in airspace Classes C, D, E, F, G and for IFR
flights in airspace Classes D, E, F, G is intended to facilitate visual acquisition of flights
which are not separated. (GM1 SERA.6001(b))
(1) A speed limit of 250 kt is applied to published SID procedures to assist in the initial
provision of separation between successive departing aircraft;
(2) A speed limit of 250 kt is applied to some STAR procedures to assist ATC in the
integration of traffic flows;
(3) Some holding patterns have non-standard maximum holding speeds for
containment within controlled airspace or separation from adjacent routes or
procedures;
(4) Some instrument approach procedures have non-standard maximum speeds for
obstacle avoidance or controlled airspace containment.
3B.2 When an aircraft is in receipt of an ATS surveillance service, except for instrument
approach procedures, controllers may relax procedure speed limits. However, extreme
caution should be exercised as the controller then becomes responsible for the provision
of separation, controlled airspace containment and obstacle clearance, which would
otherwise have been provided within the procedure design.
3B.3 Controllers should also be aware that, even if there is no tactical ATC requirement to
sustain a speed limit, particularly for departing aircraft, the pilot remains responsible for
operating his aircraft in such a manner as to adhere to other requirements, e.g. noise
preferential route track-keeping.
Table 2:
Distance from Cloud
By Day Flight Visibility
Horizontal Vertical
At and Above FL 100
(SERA.5001) 1500 m 1000 ft 8 km
Class B, C, D, E, F and G
airspace
Below FL 100 and above
3000 ft amsl or below FL
100 and above 1000 ft
above terrain, whichever
is the higher.
(SERA.5001)
Class B. C, D, E, F and G 1500 m 1000 ft 5 km
airspace
At and below 3000 ft
amsl or 1000 ft above
terrain, whichever is the
higher. (SERA.5001)
Class B, C, D and E
1500 m 1000 ft 5 km
airspace
Class F and G airspace Clear of cloud and with the surface in sight. 5 km
Alternatively, at or below
3000 ft amsl.
For aircraft, other than
helicopters, flying at 140 kt
IAS or less
Transiting Class D Clear of cloud and with the surface in sight.
airspace and remaining
outside the aerodrome
traffic zone, or aerodrome 5 km
traffic circuit
(ORS4 no. 1195)
Class G airspace Clear of cloud and with the surface in sight.
1500 m
(ORS4 no. 1067)
For helicopters flying at
140 kt IAS or less
Transiting Class D Clear of cloud and with the surface in sight.
airspace and remaining
outside the aerodrome
traffic zone, or aerodrome 1500 m
traffic circuit
(ORS4 no. 1195)
Class G airspace 1500 m
Clear of cloud and with the surface in sight
(ORS4 no. 1067)
Table 3:
At or above FL100 8 km flight visibility, 1500 m horizontal and 1000 ft vertical away
from cloud.
Below FL100 5 km flight visibility, 1500 m horizontal and 1000 ft vertical away
from cloud
Note 2: For the purposes of gliders crossing airways in VMC by day the minima will be:
At all levels 8 km flight visibility, 1500 m horizontal and 1000 ft vertical away
from cloud
Note 3: UK General Permission ORS4 no. 1067 permits the pilot in command of an aircraft to
operate in accordance with VFR within Class G airspace with a flight visibility of at least
1500 m when flying at or below 3000 ft above mean sea level, clear of cloud and in sight
of the surface with an indicated airspeed of 140 kt or less.
Note 4: UK General Permission ORS4 no. 1125 permits VFR flight within a control zone at night.
Note 5: UK General Exemption ORS4 no. 1195 enables the pilot in command of an aircraft to
transit Class D airspace in accordance with VFR by day, remaining clear of cloud with
surface in sight and an indicated airspeed of 140 kt or less, with a flight visibility of 5 km,
or for helicopters a flight visibility of 1500 m. Except for the pilot in command of a:
(i) Powerline;
(ii) Pipeline;
(iii) Police;
(iv) Helimed;
(v) SAR; or
(vi) SAR helicopter training flight operating in accordance with a Letter of Agreement
with the Air Traffic Service Provider.
ORS4 no. 1195 does not enable the pilot in command of an aircraft to transit an
aerodrome traffic zone or aerodrome traffic circuit within a control zone, when the official
meteorological report at that aerodrome indicates a ground visibility less than 5 km and/or
cloud ceiling less than 1500 ft.
Note 6: UK General Exemption ORS4 no. 1222 exempts operations of helicopters conducting
Powerline; Pipeline; Police; Helimed; Search and Rescue (SAR) flights, including SAR
training flights operating in accordance with a Letter of Agreement with the Air Traffic
Service Provider, from complying with SERA.5005(b) and SERA.5010(a) and (b).
(2) If the meteorological conditions preclude VFR flight or (within a Control Zone)
Special VFR flight.
5.2 The IFR require a pilot to observe the minimum height rule and additional rules according
to the type of airspace. These are summarised below:
(a) File a flight plan and obtain a clearance before proceeding with the flight;
(b) Conduct the flight in accordance with clearances and instructions from ATC;
(c) Maintain a listening watch on the appropriate radio frequencies; Report the
position of the aircraft according to published procedures.
Comply with the semi-circular rule ((EU) 923/2012 SERA.2025(a)) when in level flight
above 3000 feet amsl. The altimeter is set to 1013.2 hPa and the cruising level is
selected according to the magnetic track unless the aircraft is holding according to
published procedures or is otherwise instructed by ATC.
Table 4:
(1) At aerodromes with an ATC unit, all movements within the ATZ are subject to the
permission of that unit. Aircraft will comply with instructions given by RTF and
maintain a listening watch. Non-radio aircraft, which have been given prior
permission to fly within the ATZ, will comply with visual signals.
(2) At aerodromes where an AFIS or AGCS is provided, pilots shall obtain information
from the unit to enable the flight to be conducted safely within the zone and maintain
a listening watch. Non-radio aircraft must comply with any conditions prescribed by
the unit prior to the commencement of the flight.
6.2 Controllers who need to ascertain whether a pilot will either route around or transit through
an ATZ in Class G airspace should advise the pilot of the ATZ status and confirm the
pilot’s intentions. Controllers may advise pilots to change to the published aerodrome RT
frequency to either obtain ATZ crossing clearance from an ATC unit, or to obtain
information from an AFIS or AGCS unit.
Note 2: Cancelling an IFR flight in Class E airspace simultaneously cancels the provision of an Air
Traffic Control Service; see CAP 774 for types of UK FIS available in Class E Airspace.
7.2 Controllers are to acknowledge a cancellation using the phrase “IFR plan cancelled at
(time)”. (GM1 SERA.5015(c)(3))
7.3 Pilots cancelling IFR plans shall be given any information which indicates that IMC may be
encountered along the intended route.
7.4 ATS units receiving notification of an aircraft’s intention to change from IFR to VFR flight
shall, as necessary, by automated means or otherwise, inform subsequent ATS units of
the IFR flight plan cancellation.
8A. Conditions
8A.1 A Special VFR clearance is issued when requested by a pilot or when it is notified in the
UK AIP for a particular type of operation. Before issuing such a clearance a controller
must consider the prevailing traffic conditions, the extent of the proposed flight and the
availability of air-ground communications. Special VFR flights are not to hinder normal IFR
flights.
8B. Weather
8B.1 When the reported meteorological conditions at aerodromes in Class D airspace reduce
below a ground visibility of 1500 m and/or a cloud ceiling of 600 ft, both by day or night,
ATC shall advise pilots of aircraft intending to operate under Special VFR to or from such
aerodromes, and request the pilot to specify the type of clearance required.
8B.2 Except for helicopters using Police; Helimed; Rescue; Electricity; Grid; Powerline, or
Pipeline callsigns,or a SAR training flight operating in accordance with MATS Part 2,
controllers shall not issue a SVFR clearance to aircraft wishing to operate under SVFR to
or from an aerodrome within a control zone, or enter the aerodrome traffic zone or
aerodrome traffic circuit, when the official meteorological report at that aerodrome
indicates:
(a) Aircraft other than helicopters: ground visibility less than 1500 m and/or cloud
ceiling less than 600 feet (SERA.5010(c));
(b) Helicopters: ground visibility less than 800 m and/or cloud ceiling less than 600
feet (SERA.5010(c)).
Note 1: When the reported ground visibility at the aerodrome is less than 1500 m, ATC may issue
a Special VFR clearance for a flight crossing the control zone and not intending to take off
or land at an aerodrome within a control zone, or enter the aerodrome traffic zone or
aerodrome traffic circuit when the flight visibility reported by the pilot is not less than 1500
m, or for helicopters, not less than 800 m (GM1 SERA.5010(c))
Note 2: UK General Permission ORS4 no. 1125 permits SVFR flight within a control zone at night.
Note 3: UK General Exemption ORS4 no. 1222 exempts operations of helicopters conducting
Powerline; Pipeline; Police; Helimed; Search and Rescue (SAR) flights, including SAR
training flights operating in accordance with a Letter of Agreement with the Air Traffic
Service Provider, from complying with SERA.5005(b) and SERA.5010(a) and (b).
Note 4: For the purpose of observing the meteorological conditions at an uncontrolled and/or
unlicensed aerodrome or operating site located within a control zone, and assessing
whether those conditions satisfy the minima specified in SERA.5005(b) and SERA
5010(c) as appropriate, the Civil Aviation Authority deems the following to be competent to
act as ‘accredited observers’ as required within Regulation (EU) 923/2012 Article 2(28) for
their flight:
(a) The holders of valid EASA Flight Crew Licences, valid National Flight Crew Licences
and Certificates issued by, or on behalf of, the United Kingdom Civil Aviation
Authority, and third country licences deemed valid in accordance with Article 150 of
the Air Nagivation Order 2016; and
(b) A student pilot-in-command (SPIC) who has passed the theoretical knowledge
examination in meteorology toward the grant of an EASA Flight Crew Licence or
National Flight Crew Licence or Certificate issued by, or on behalf of, the United
Kingdom Civil Aviation Authority within the preceding two years.
8B.3 When the reported ground visibility consists of two values, the lower of the two values
shall be used when determining if a Special VFR clearance can be issued.
8B.4 Procedures for operations into subsidiary aerodromes will be found in MATS Part 2.
8B.5 Aircraft flying along promulgated routes may encounter deteriorating weather conditions.
Controllers should be prepared to provide an alternative route to enable the pilot to
comply with the conditions of a Special VFR clearance.
8C. Separation
8C.1 Standard separation is to be applied between:
(2) Aircraft cleared for Special VFR flights (except where a reduction is authorised by
the CAA).
8C.2 No separation can be provided between Special VFR flights which are flying in notified
areas or routes where an individual clearance is not required, or between flights using
such areas or routes and other flights on Special VFR clearances.
(2) is responsible for ensuring that his flight conditions enable him to remain clear of
cloud, determine his flight path with reference to the surface and keep clear of
obstructions;
(3) is responsible for ensuring that he flies at an indicated airspeed of 140 kt or less in
order to provide adequate opportunity to observe any obstacles in time to avoid a
collision (SERA.5010(b)(3));
(4) is responsible for ensuring that he flies within the limitations of his licence;
(5) is responsible for complying with the relevant RoA low flying restrictions (other than
the 1000 feet rule);
(6) is responsible for avoiding Aerodrome Traffic Zones unless prior permission for
penetration has been obtained from the relevant ATC unit.
9. Class C Airspace
9.1 The airspace classification between FL195 and FL660 within the UK FIRs / UIRs is Class
C. However, the FIR / UIR boundary is FL245.
9.2 Controllers shall not allocate FL195 as a cruising level to any aircraft under their control.
(1) A flight plan must be filed. Abbreviated flight plans for civil aircraft are permissible as
described in UK AIP (ENR) section and MATS Part 1. For military aircraft,
abbreviated flight plans will only be acceptable when operating under the control of
a military ATSU or Air Surveillance and Control System (ASACS) unit;
(4) Mandatory carriage of 8.33 kHz capable radio equipment in controlled airspace
above FL195;
9A.2 Above FL195 in Class C airspace the semi-circular rule shall apply. Flight Levels 200, 220
and 240 shall be westbound and Flight Levels 210 and 230 shall be eastbound.
9B.2 For separation purposes, controllers must treat all flights as IFR until such time as the
flight rules are ascertained.
9B.3 Unit specific procedures for the avoidance of collisions between VFR flights shall be
detailed in MATS Part 2s and shall be subject to the following conditions:
(1) The VFR status of aircraft is to be established. Pilots will inform controllers when
they wish to operate VFR and when VFR operations are complete.
(2) Military aircraft formations, in accordance with extant procedures, will remain
responsible for separation within their formation (MARSA).
9C.2 The pilot on first RTF contact should notify the VFR status of the flight. En route VFR
flights above FL195 are not permitted unless they have been accorded specific
arrangements by the appropriate ATS authority. VFR flights shall only be authorised:
(1) in TRAs; or
(2) outside of a TRA, by the responsible ATSU in accordance with the procedures
established and published in the UK AIP. Civil air traffic above FL285 will only be
permitted to operate VFR within airspace defined by an airspace reservation.
9D.2 Procedures for operators of civil aircraft requiring VFR access to Class C airspace above
FL195 are detailed in the UK AIP and for military aircraft in the Military AIP and the
Manual of Military Air Traffic Management.
(2) Abbreviated flight plans; the limited information required to obtain a clearance for a
portion of flight, e.g. flying in a control zone, crossing an airway etc. filed either on
the RTF or by telephone prior to take-off.
10.2 The local ATSU may assist in compiling flight plans and checking them. However, the
ultimate responsibility for filing an accurate flight plan rests with the pilot or aircraft
operator.
10.3 The destination aerodrome will be advised of the flight only if the flight plan information
covers the whole route of the flight.
10.4 An airborne flight plan may be filed provided that the pilot leaves sufficient time for the
clearance to be issued before the aircraft reaches the boundary of controlled airspace
(normally 10 minutes).
10.6 A pilot is required to file a flight plan for ((EU) 923/2012 SERA.4001(b)):
(1) any flight or portion thereof to be provided with an air traffic control service;
(3) any flight within or into areas, or along routes designated by the Authority, to
facilitate the provision of flight information, alerting and search and rescue services;
(4) any flight within or into areas or along routes designated by the Authority, to facilitate
coordination with appropriate military units or with air traffic service units in adjacent
States in order to avoid the possible need for interception for the purposes of
identification prescribed by the States concerned;
Note: For the purposes of (EU) 923/2012 SERA.4001(b)(5) ‘Submission of a flight plan’ in the
UK, the international borders for flight planning purposes are the international FIR
boundaries.
(6) any flight planned to operate at night, if leaving the vicinity of an aerodrome.
(1) if his flight involves flying over the sea more than 10 miles from the UK coast or
flying over sparsely populated areas where SAR operations would be difficult; or
(2) if he intends to fly into an area in which SAR operations are in progress. The flight
plan should include the expected times of entering and leaving the area and the
details must also be passed to the parent ACC. The ACC is to notify the ARCC
concerned.
10.8 A pilot who has filed a flight plan to a destination without an ATSU and not connected to
the AFTN shall comply with the following procedure:
(1) Nominate a responsible person at his destination and inform him of the planned
ETA. If the aircraft fails to arrive within 30 minutes of the ETA the responsible
person will notify the parent ATSU. That ATSU will then initiate Alerting action; or
(2) If no responsible person can be found, the pilot will contact the parent ATSU and
request that they act in the same capacity. The pilot is then required to inform the
parent ATSU of his arrival within 30 minutes of the notified ETA, otherwise Alerting
action will automatically be initiated.
13.2 If the ATSU at the departure aerodrome closes before ETA at destination plus one hour,
the senior controller shall forward the details contained in field 19 of the flight plan form to
the parent ACC ensuring that any change to the endurance or number of persons on
board is included.
14. Booking-Out
14.1 Pilots who do not file a flight plan, either full or abbreviated, are required to inform the
ATSU at the aerodrome of their departure. This is referred to as booking-out. The ATSU is
to record the departure. No further action is required.
15.2 Requests for non-standard flights, e.g. photographic surveys above 1500 feet agl, should
be referred to the appropriate addressee (UK AIP (ENR) section).
16.2 If the pilot wishes to file the report by RTF the controller should, whenever possible,
accept the relevant details, particularly when the flight is bound for a foreign destination. If,
due to the controller’s high workload, this cannot be done the pilot is to be requested to
file the details after landing.
16.3 The senior controller is then responsible for taking follow-up action.
16.4 The pilot’s report by RTF should commence with the term “AIRPROX Report”. If the pilot
omits the prefix the controller shall ask him if it is his intention to file an AIRPROX report.
The complete message will comprise:
(5) Heading;
(6) Brief details of incident including first sighting and miss distance;
16.5 If the pilot states that he intends to file an AIRPROX report after landing he is to be
reminded that, to avoid any delay in its progression, the details are required as soon as
possible after he has landed.
16.6 Controllers must not offer opinions as to cause or responsibility, either to pilots at the time
or to operators or pilots subsequently. Pilots may be told that the incident will be
investigated.
16.7 The identity of the reported aircraft is to be established as soon as possible by any
practical means. If the identity is not immediately apparent the senior controller is to be
advised so that he can commence search action.
16.8 Full reporting action after the receipt of an AIRPROX report is described in Section 6.
17.2 Data is to be examined, other units consulted and every means used consistent with
safety in an attempt to identify the aircraft. ATS surveillance systems should be used to
track the aircraft until it has landed and the track and time correlated with movement at the
appropriate aerodrome. If necessary, the aircraft’s position indication may be transferred
to another unit to enable tracking to be continued.
(1) Normally permission should only be granted if flight is to be continued wholly within
UK controlled airspace classes A-D. Flight outside the UK under these conditions
may not be authorised unless permission to continue has been obtained from the
adjacent controlling authority;
(2) If the pilot’s intention is to fly outside controlled airspace or within Class E airspace,
he should be instructed to land at the nearest suitable aerodrome. Selection of this
aerodrome is the responsibility of the pilot although he may request information to
assist him in making his decision. Under certain circumstances the pilot may decide
that the nearest suitable aerodrome is his original destination.
20.2 The action taken at the ACC, which includes warning aircraft in flight, is described in
MATS Part 2.
21.2 Flights operating in airspace designated as an RMZ by the CAA, shall establish two-way
communication before entering the dimensions of the RMZ and maintain continuous air-
ground voice communication watch, as necessary, on the appropriate communication
channel, unless in compliance with alternative provisions prescribed for that particular
airspace by the Controlling Authority. If unable to establish two-way radio communication
with the designated RMZ Controlling Authority the pilot is to remain clear of the RMZ.
21.3 Two-way communication is considered to have been achieved once the pilot has provided
at least the following information on the appropriate communications channel:
(1) Callsign;
(3) position;
21.4 When taking off from a site within the RMZ where communications prior to getting
airborne are not possible, the pilot shall, whilst maintaining compliance to published local
Letters of Agreement or Memoranda of Understanding, establish two-way communication
with the RMZ Controlling Authority at the earliest opportunity once airborne.
21.5 The pilot of an aircraft that wishes to operate in an RMZ without the necessary radio
equipment is to operate in accordance with conditions promulgated for the specific RMZ
or in accordance with agreed tactical arrangements with the RMZ Controlling Authority
and if a pilot is unable to make such tactical arrangements he is to remain clear of the
RMZ, unless in an emergency.
SECTION 1: CHAPTER 3
Separation Standards
(5) Special VFR flights, except where a reduction is authorised by the CAA.
1.2 Standard separation shall be provided, in so far as possible, between aircraft that have
flight planned to operate IFR on Class F ADR airspace.
1.3 In Class G airspace, separation between aircraft is ultimately the responsibility of the pilot;
however, in providing a Deconfliction Service or a Procedural Service, controllers will
provide information and advice aimed at achieving a defined deconfliction minima.
2. Increased Separation
2.1 Separation standards are minima and shall be increased when:
3. Reduced Separation
3.1 In addition to the following paragraphs, standard separation may be reduced when
authorised by the CAA and published in MATS Part 2.
(1) adequate separation can be provided by the aerodrome controller when each
aircraft is continuously visible to this controller; or
(2) each aircraft is continuously visible to the pilots of other aircraft concerned and the
pilots report that they can maintain their own separation; or
(3) when one aircraft is following another, the pilot of the succeeding aircraft reports that
he has the other aircraft in sight and can maintain own separation.
(1) use every means at his disposal to obtain the required minimum with the least
possible delay; and
(2) when considered practicable, pass traffic information if an ATS surveillance service
is being provided, otherwise, pass essential traffic information.
(3) Cruising level of conflicting aircraft and ETA for the reporting point, or for aircraft
passing through the level of another with less than the normal separation; the ETA
for the reporting point nearest to where the aircraft will cross levels; and
5. Vertical Separation
(b) Above FL290 apply 2000 feet, except that between FL290 and FL410 inclusive,
1000 feet may be applied between RVSM approved aircraft operating in
airspace designated as being notified for the application of this separation
standard.
(2) Between aircraft flying supersonic and between aircraft flying supersonic and aircraft
flying subsonic:
5A.2 In the event of a pilot advising that his aircraft is no longer capable of RVSM operations, it
is particularly important that the first ATSU made aware of the failure performs the
necessary co-ordination with subsequent ATSUs.
5A.3 The Mode C of some military aircraft is accurate only to the nearest 400 feet during
supersonic flight. On occasions, therefore, military controllers may have to apply 4000 feet
separation at all levels.
5A.4 Controllers are to assess the vertical distance between aircraft by observing the Mode C
responses in accordance with the conditions for the use of Mode C specified in Chapter 6
or by obtaining level reports from pilots.
(2) the vacating aircraft is proceeding to a level that will maintain vertical separation;
and
(3) either:
(a) the controller observes that the vacating aircraft has left the level; or
5B.3 If severe turbulence is known to exist, instructions shall be delayed until the vacating
aircraft is known to be at, or through, another level separated by the required minimum.
5B.4 Controllers shall exercise caution when instructing an aircraft to climb or descend to a
previously occupied level. Consideration shall be given to the fact that aircraft may climb
or descend at markedly different rates and, if necessary, additional measures such as
specifying a maximum or minimum climb or descent rate for each aircraft shall be applied
to ensure that the required separation is maintained. This is particularly relevant when the
aircraft concerned are established in the same holding pattern.
5B.5 Pilots in direct communication with each other may, with their concurrence, be instructed
to maintain a specified vertical separation between aircraft during climb or descent.
(4) the pilot of the aircraft climbing or descending agrees to maintain his own separation
from other aircraft and the manoeuvre is agreed by the pilot of the other aircraft; and
5C.2 The application of VMC climb and descent could result in TCAS RA being triggered.
Therefore, in Class D airspace when surveillance services are being provided, VMC climb
and descent shall only be used where authorised and in accordance with any conditions
specified in MATS Part 2.
6. Horizontal Separation
6.1 The three types of horizontal separation are:
6A.2 An ‘exact reporting point’ is a position established by a navigational facility which is:
(3) a position notified as a reporting point and which is established by the intersection of
VOR radials, or of a VOR radial and a bearing from an NDB;
(4) a position established by a VOR radial combined with a range from a co-located or
associated DME.
6B.2 Communication must be maintained with the aircraft concerned throughout the period that
measured distance values are being used to achieve separation. Separation is to be
checked by obtaining simultaneous DME/TACAN readings from aircraft at intervals of not
more than 10 minutes.
6B.3 VOR/DME/TACAN separation criteria are based on the condition that a VOR and its
associated DME/TACAN station are within 5 miles of each other. Where this distance is
exceeded, special separation criteria will be published in MATS Part 2.
7. Lateral Separation
7.1 Lateral separation shall be applied so that the distance between aircraft is never less than
a specified amount. It is achieved by requiring aircraft to fly on different tracks or in
different geographical locations as determined by visual observations or by use of
navigational aids.
(1) Using a VOR and associated DME/TACAN station. Both aircraft must have reported
established on radials at least 20° apart;
(2) Using VOR radials. When one aircraft is a time equivalent of 15 miles or 4 minutes
(whichever is the greater) from the VOR and both aircraft have reported established
on radials which diverge by 20° or more;
Aircraft diverging
(3) Using VOR radials. Both aircraft must have passed a VOR on tracks diverging by
45° or more and have reported established on the relevant radials;
Aircraft diverging
(4) Using specified tracks from an NDB. When one aircraft is the time equivalent of 15
miles or 4 minutes (whichever is the greater) from an NDB and both aircraft have
reported established on tracks which diverge by 30° or more.
Aircraft diverging
Note: If a pilot reports that he suspects the accuracy of the NDB indications this separation shall
not be used.
(1) indicated by position reports over different geographical locations that have been
specified in MATS Part 2 as being separated; and
8.1 Longitudinal separation based on either time or distance shall be applied so that the
spacing between the estimated positions of the aircraft being separated is never less than
a prescribed minima. It is achieved by requiring aircraft to:
8.2 For the purpose of application of longitudinal separation, the terms below shall have the
following meanings:
(1) ‘Same track’, when the track of one aircraft is separated from the track of the other
by less than 45°;
(2) ‘Reciprocal track’, when the track of one aircraft is separated from the reciprocal of
the other by less than 45°;
(3) ‘Crossing track’, intersecting tracks which are not classed as ‘same’ or ‘reciprocal’.
Minimum
Aircraft En Route Provisions
Separation**
Provided the 2 minute departure separation has been
2 minutes*
applied (see separate table).
When specifically authorised by the CAA provided both
aircraft are:
(1) equipped with functioning transponders; and
Same cruising level 3 minutes*
and same track (2) continuously monitored by radar and the
actual distance between them is never less
than 20 miles.
Minimum
Aircraft En Route Provisions
Separation**
When specifically authorised by the CAA, provided both
aircraft are:
5 minutes* (1) equipped with functioning transponders; and
10 minutes –
5 minutes* Provided that the level change is commenced within 10
Climbing and
at time levels minutes of the time the second aircraft has reported over
descending on the
are crossed the same exact reporting point.
same track
10 minutes –
Crossing tracks 10 minutes –
Vertical separation shall be provided for at least 10
minutes both prior to and after the estimated time of
passing unless it is confirmed that the aircraft have
actually passed each other by:
(1) ATS surveillance system derived
10 minutes information;***
before and after
Reciprocal tracks (2) a visual sighting report from both pilots (by
estimated
passing time day only); or
** Separation minima based on time cannot be achieved unless the whole sixty seconds of each minute specified is permitted to elapse.
*** When confirmation has been obtained from ATS surveillance system derived information that aircraft on reciprocal tracks have
passed, there is no requirement to ensure that minimum horizontal separation exists before reducing minimum vertical separation.
8B.2 Separation based on DME/TACAN is not to be used when aircraft are within 15 miles of
the overhead of the facility. Slant range errors beyond 15 miles may be ignored.
Aircraft En Minimum
Provisions
Route Separation
Provided the preceding aircraft maintains a true airspeed of 20
15 miles knots or more faster than the following aircraft and both are
within 100 miles of the DME/ TACAN station.
Same cruising
Provided the preceding aircraft maintains a true airspeed of 20
level and 20 miles
knots or more faster than the following aircraft.
same track
Provided both aircraft are within 100 miles of the DME/TACAN
20 miles
station.
25 miles –
Climbing or Provided that one aircraft maintains level flight while vertical
15 miles at the
descending separation does not exist.
time levels are
on the same
crossed
track
The 40 mile separation need not apply if it has been established
that the aircraft have passed each other and are at least 10
Reciprocal miles apart.
40 miles
tracks
The 10 miles may be further reduced to 5 miles when both
aircraft are within 100 miles of the DME/TACAN station.
8D.2 The minima in the table are complementary to the en route longitudinal separations based
on time. Greater minima than that listed below may be required for wake turbulence
separation purposes.
Minimum
Provisions
Separation*
Provided that the aircraft fly on tracks diverging by 45° or more immediately
after take-off.
1 minute
The minimum may be reduced when aircraft are taking-off from independent
diverging or parallel runways provided the procedures have been approved by
the CAA.
Provided that:
(1) the preceding aircraft has filed a true airspeed 40 knots or more
faster than the following;
2 minutes
(2) neither aircraft is cleared to execute any manoeuvre that would
decrease the 2 minute separation between them.
Provided that the preceding aircraft has filed a true airspeed of 20 knots or
5 minutes
more faster than the following aircraft.
Provided that the 5 minutes separation is maintained up to a reporting point,
within or adjacent to a control zone or terminal control area and the aircraft will
subsequently be separated either:
(1) vertically;
5 minutes
(2) by tracks which diverge by 30° or more; or
(3) by radar.
(1) the en route aircraft has filed a true airspeed of 20 knots or more faster than the
departing aircraft; and
(2) the en route aircraft has reported over an exact reporting point at which the
departing aircraft will join the same route; and
(3) the departing aircraft is given positive instructions to arrive at the same exact
reporting point 5 minutes behind the en route aircraft.
9A. General
9A.1 In radiotelephony, the term ‘wake turbulence’ shall be used to describe the effect of the
rotating air masses generated behind the wing tips of aircraft, in preference to the term
‘wake vortex’ which describes the nature of the air masses.
9A.2 All aircraft, including helicopters, generate vortices as a consequence of producing lift.
The heavier the aircraft and the more slowly it is flying, the stronger the vortex. Vortices
are especially persistent in calm conditions. They are most hazardous to aircraft with a
small wingspan during the take-off, initial climb, final approach and landing phases of
flight.
9A.3 Wake vortices begin to be generated by fixed-wing aircraft when the nose wheel lifts off
the runway on take-off and continue until the nose wheel touches down on landing.
9A.4 When helicopter weight is transferred from the landing gear to the rotor a strong
downwash is created in all directions, although this can be moved by the wind. When
helicopters are in forward flight the downwash from the main rotor(s) is transformed into a
pair of trailing vortices similar to the wing tip vortices of a fixed wing aircraft. There is
some evidence that these vortices are more intense than for comparable fixed-wing
aircraft.
9A.5 UK wake turbulence categories are listed in Appendix B. It should be noted that they differ
from the ICAO categories, which are used for flight plan purposes.
9B. Applicability
9B.1 Wake turbulence separation minima are the spacings between aircraft, determined either
by time or distance, to be applied so that aircraft do not fly through the wake of a
preceding aircraft within the area of maximum vortices.
9B.2 Where the separation minima required for IFR flights are greater than the recommended
separation for wake turbulence, the IFR separation minima shall be applied.
9B.3 When a flight is operating visually (i.e. IFR or SVFR operating under the reduced
separation in the vicinity of aerodromes, VFR, or IFR making a visual approach) and is
following or crossing behind another aircraft, the pilot is to be informed of the
recommended wake turbulence separation minima.
9C. En route
9C.1 No special longitudinal wake turbulence separations based on time are required.
9C.2 The following surveillance based wake turbulence separation minima shall be applied in
en route flight:
(1) minimum of 5 NM between a Heavy (including A380-800) and a Medium (Upper and
Lower), Small or Light aircraft following or crossing behind at the same level or less
than 1000 ft below.
(1) 5 NM between a Heavy (excluding A380-800) and a Medium (Upper and Lower) or
Small aircraft following or crossing behind at the same level or less than 1000 ft
below;
(2) 6 NM between a Heavy (excluding A380-800) and Light aircraft following or crossing
behind at the same level or less than 1000 ft below;
(3) As per Final Approach minima for aircraft following or crossing behind an A380-800
at the same level or less than 1000 ft below.
Note: The intermediate approach phase is specific to each individual Instrument Approach
Procedure. Therefore, ATC units should define and specify in MATS Part 2 the area or
portion of a procedure where the intermediate approach wake turbulence separation
minima apply.
(1) an aircraft is operating directly behind another aircraft at the same altitude or less
than 1000 ft below; or
(2) an aircraft is crossing behind another aircraft, at the same altitude or less than 1000
ft below; or
(3) both aircraft are using the same runway or parallel runways separated by less than
760 m.
Table 3:
9F. Departures
9F.1 Wake turbulence separation minima on departure shall be applied by measuring airborne
times between successive aircraft. Take-off clearance may be issued with an allowance
for the anticipated take-off run on the runway; however, the airborne time interval shall
reflect a difference of at least the required time separation.
9F.2 Unless alternative wake turbulence separation criteria are approved and contained in
MATS Part 2, the wake turbulence separation minima in the table below shall be applied
when aircraft are using (SERA.8012):
(2) parallel runways separated by less than 760 m; orcrossing runways if the projected
flight path of the second aircraft will cross the projected flight path of the first aircraft
at the same altitude or less than 1000 ft below; or
(3) parallel runways separated by 760 m or more, if the projected flight path of the
second aircraft will cross the projected flight path of the first aircraft at the same
altitude or less than 1000 ft below.
Table 4:
Note: ATC shall apply the minima as prescribed above, irrespective of any pilot request for
reduced wake turbulence separation. ATC does not have the discretion to reduce wake
turbulence separation minima.
(2) landing on the same runway in the opposite direction, or on a parallel opposite-
direction runway separated by less than 760 m.
9G.2 Other aircraft categories. A wake turbulence separation of 2 minutes shall be applied
between a Medium (Upper and Lower), Small or Light aircraft and a Heavy aircraft, and
between a Medium (Upper and Lower) or Small aircraft and a Light aircraft whenever the
heavier aircraft is making a low or missed approach and the lighter aircraft is:
(2) landing on the same runway in the opposite direction; or on a parallel opposite
direction runway separated by less than 760 m.
9H.2 The wake turbulence separation minima listed in paragraph 9G will apply to:
(1) departures from crossing and/or diverging runways if the projected flight paths will
cross; or
(2) departures from parallel runways 760 m or more apart if the projected flight paths
will cross.
(1) a departing Light, Small or Medium (Upper and Lower) aircraft follow an A380-800
aircraft arrival; or
(2) an arriving Light, Small or Medium aircraft follow an A380-800 aircraft departure.
9I.2 A380-800. If the projected flight paths are expected to cross, a wake turbulence
separation of 2 minutes shall be applied between a Heavy aircraft and an A380-800
aircraft when operating on a runway with a displaced landing threshold when:
Note: The wake turbulence separation criteria specified above are interim UK criteria
until ICAO publish guidance in this area.
9I.3 Other aircraft categories. If the projected flight paths are expected to cross, a wake
turbulence separation of 2 minutes shall be provided between Medium (Upper and
Lower), Small or Light aircraft following a Heavy aircraft and between a Light aircraft
following a Medium or Small aircraft when operating on a runway with a displaced
threshold when:
(1) a departing Medium (Upper and Lower), Small or Light aircraft follow a Heavy arrival
or a departing Light aircraft follows a Medium or Small arrival; or
(2) an arriving Medium (Upper and Lower), Small or Light aircraft follow a Heavy aircraft
departure, or an arriving Light aircraft follows a departing Medium or Small aircraft.
9K. Helicopters
9K.1 For wake turbulence separation purposes, helicopters air taxiing across runways shall be
considered to be a departure from that intermediate point of the runway.
9K.2 When hovering or air taxiing, a helicopter directs a forceful blast of air downwards which
then rolls out in all directions. This downwash and associated turbulence can drift a
substantial distance downwind and may affect an adjacent runway or taxiway. To
minimise the effects of this turbulence controllers should:
(1) instruct helicopters to ground taxi rather than air taxi when operating in areas where
aircraft are parked or holding;
(2) not air-taxi helicopters close to taxiways or runways where light aircraft operations
(including light helicopter operations) are in progress. If air taxiing is imperative,
helicopters must be routed to:
(a) avoid over flying parked aircraft, vehicles or loose ground equipment;
(b) follow standard taxi routes where helicopters and fixed wing aircraft share
common areas on a movement area;
9K.3 When a helicopter is hover taxiing or in a stationary hover controllers should avoid taxiing
light aircraft or helicopters within a minimum area comprising three times the rotor
diameter of that helicopter. Controllers should consider this to be a minimum distance
which will need to be increased for larger helicopters.
9K.4 Caution should be exercised when a helicopter or fixed-wing aircraft of a lower weight
turbulence category is cleared to land on a runway immediately after a helicopter of higher
weight turbulence category has taken off from that runway’s threshold.
10.1 Horizontal separations based on ATS surveillance system information shall be justified by
the ANSP, approved by the CAA and detailed in MATS Part 2.
10.2 Horizontal separation based on ATS surveillance system information shall not be used
between aircraft holding over the same holding point.
10.3 Where there is a requirement for an increase in separation between aircraft prior to
transfer, this shall be documented and applied in accordance with MATS Part 2.
10A.2 When approved by the CAA, separation based on radar derived information may be
applied between an aircraft taking-off and a preceding departing aircraft, or other aircraft
in receipt of an ATS surveillance service, provided there is a reasonable assurance that
the departing aircraft will be identified within one mile from the end of the runway and that,
at the time, the required separation will exist.
(2) to overcome temporary deficiencies within PSR cover, such as fading or clutter, the
SSR return only of one aircraft may be used to provide separation from the PSR or
SSR return of another aircraft provided the PSR and SSR situation displays are
correctly aligned. In this context, ‘unavailable for use due to maintenance’ does not
constitute a ‘temporary deficiency’;
(3) immediately after PSR failure for the minimum time necessary to establish
procedural separation. Once established, services normally provided using radar
may be resumed when the PSR is serviceable.
10B.2 SSR shall not be used to provide horizontal separation if a controller has any doubt about
the accuracy of the position symbol due to equipment malfunction, reflections or any other
reason.
Intentionally blank
CAP 493
SECTION 1: CHAPTER 4
Control of Traffic
1.2 An ATC clearance authorises an aircraft to proceed under conditions specified by an ATC
unit. Clearances are based solely on known traffic conditions and are required for any
flight, or portion of a flight, which is provided with an air traffic control service
(SERA.8015(a)). Such traffic conditions include not only aircraft in the air and on the
manoeuvring area over which control is being exercised, but also any vehicular traffic or
other obstructions not permanently installed on the manoeuvring area in use
(SERA.8015(a)(1)).
1.3 A pilot requests a clearance by submitting a flight plan (SERA.8015(b)(1). The clearance
can be issued directly to the aircraft or through an approved agency, such as another
ATSU. The pilot shall inform ATC if an air traffic control clearance is not satisfactory, and
in such cases, controllers will issue an amended clearance, if practicable
(SERA.8015(b)(2)).
1.4 Clearances do not constitute authority to violate any regulation established by the DfT,
CAA, or other appropriate authority for promoting safety of flight operation or for any other
purpose. Controllers should not issue clearances which imply permission to breach
regulations. This is especially relevant in respect of the low flying rules.
1.5 Where data link communications are used to facilitate clearance delivery, two-way voice
communications between the pilot and the air traffic control unit providing the clearance
should be available. Unless specified in the MATS Part 2, voice read-back of data link
messages shall not be required.
2. Contents of Clearances
(4) Levels of flight for the entire route or part thereof and changes of levels if required;
Note: Where an airborne joining clearance to enter controlled airspace is provided, the joining
level assigned is considered acceptable with respect to the level content of a clearance.
Note: The time of expiry of the clearance indicates the time after which the clearance will be
automatically cancelled if the flight has not been commenced. (GM1.SERA.8015(d)(5))
2.2 The form that the clearance message shall take is described in CAP 413 Radiotelephony
Manual.
3. Clearance Limit
3.1 A clearance limit is the point to which an aircraft is granted an ATC clearance and shall be
specified by naming:
(1) an aerodrome;
3.2 An aircraft shall be cleared for the entire route to the aerodrome of first intended landing
when:
(1) it has planned to remain within controlled or advisory airspace throughout the flight;
and
(2) there is reasonable assurance that prior co-ordination will be effected ahead of the
passage of the aircraft.
3.3 The clearance limit for all other flights shall be the boundary of controlled or advisory
airspace.
3.4 If the clearance for the levels covers only part of the route, it is important to specify that
part to enable the pilot to comply with the radio failure procedures.
3.5 The CAA may issue special instructions concerning the clearance of inbound aircraft to
certain aerodromes.
4. Conditional Clearances
4.1 Conditional clearances are to be given in the following order and are to comprise
(SERA.8015(ec)):
(3) identification of the subject of the condition, e.g. aircraft, reporting point, level etc;
“(Callsign), behind the landing (aircraft type), via (holding point), runway (designator)
line up behind.”.
4.3 Use of conditional clearances at aerodromes, especially with regard to active runways, is
detailed in Section 2.
5. Route
5.1 Every endeavour shall be made to clear aircraft according to the route requested. If this is
not possible the controller shall explain the reason when issuing the clearance. The
expression “cleared flight plan route” is not to be used for re-clearances.
(SERA.8015(d)(3)(ii))
5.2 If a pilot requests, or a controller offers, a direct routeing then the controller must inform
the pilot if this direct route will take the aircraft outside the lateral or vertical boundaries of
controlled or advisory airspace. The pilot will then decide whether to accept or decline the
new route.
5.3 When traffic conditions do not permit clearance of a pilot’s requested change in route,
controllers shall use the word “unable” in RTF phraseology (SERA.8015(ea)(2)).
5.4 Following the introduction of area navigation requirements (RNAV), aircraft wishing to
operate within the specified airspace must be appropriately equipped. If the aircraft is
unable to comply with the RNAV requirements then the pilot will advise the ATSU on initial
contact using the phrase “Negative RNAV”. Aerodrome ATSUs must advise the relevant
ACC and, unless automatic message transfer facilities exist, the phrase “Negative RNAV”
must be added to the end of estimate and co-ordination messages.
6.1 Normally, the cruising level requested in the flight plan is to be allocated. If the flight
planned level is not available, the nearest appropriate vacant level is to be allocated.
6.2 When two or more aircraft are at the same cruising level, the preceding aircraft shall
normally have priority.
6.3 An aircraft at a cruising level shall normally have priority over other aircraft requesting that
level.
6.4 When traffic conditions do not permit clearance of a pilot’s requested change in level,
controllers shall use the word “unable” in RTF phraseology and offer an alternative level
(SERA.8015(ea)(2)).
6A.2 Above FL195 in Class C airspace the semi-circular rule shall apply. Flight Levels 200,
220, 240, 260 and 280 shall be westbound; Flight Levels 210, 230, 250 and 270 shall be
eastbound.
6A.3 Cruising levels at or above FL290, up to FL410 within RVSM designated airspace shall be
selected according to the tables below:
Table 1:
(1) in receipt of a Deconfliction Service and being provided with vertical and/or lateral
deconfliction advice;
(4) provided with level and/or heading allocations for positioning and sequencing;
7. Amendments to Clearances
7.1 When an amendment is made to a clearance the new clearance shall be read in full to the
pilot and shall automatically cancel any previous clearance. Controllers must be aware,
therefore, that if the original clearance included a restriction, e.g. “cross ABC FL150 or
below” then the issue of a revised clearance automatically cancels the earlier restriction,
unless it is reiterated with the revised clearance.
7.2 Similar care must be exercised when a controller issues a clearance, which amends the
vertical profile of an aircraft on an SID. For example, “climb now FL120” automatically
cancels the vertical profile of the SID. If the profile contains a restriction that provides
vertical separation from conflicting traffic on another SID, the restriction must be
reiterated,
e.g. “climb now FL120 cross XYZ 5000 feet or above”, unless separation is ensured by
other means.
7.3 Similarly, when controllers issue instructions which amend the SID route, they are to
confirm the level profile to be followed, e.g. “fly heading 095, climb now FL80” or “route
direct EFG, stop climb at altitude 5000 feet”.
8. Withholding Clearance
8.1 The Aerodrome Operator and certain other persons are empowered to prohibit flight and
they may instruct controllers to withhold a clearance. A list of the personnel authorised
under civil aviation legislation and the procedures to be adopted when detaining aircraft
appear in unit instructions.
8.2 If a controller is instructed to withhold take-off clearance, he should take reasonable steps
to establish the authenticity and powers of the person giving the instruction.
8.3 In addition a controller shall withhold clearance to take-off when it is known that an aircraft
has been detained by a police or HM Customs officer.
8.4 If a controller has not been instructed to withhold clearance but he has reason to believe
that a planned flight is liable to endanger life or involve a breach of legislation, he is to:
(1) warn the pilot of the hazardous condition or apparent infringement and obtain an
acknowledgement of the message;
(2) in the case of an infringement of legislation, warn the pilot that if he does take-off the
facts will be reported to the appropriate authority;
(3) if the pilot still requests take-off clearance after acknowledging the warning he
should be advised, when traffic permits, that there are no traffic reasons to restrict
take-off;
(4) record the warning and any comment made by the pilot in the ATC Watch Log
8A. Phraseology
8A.1 Because of possible legal action when pilots disregard the warnings described above, or
when aircraft which have been detained depart without clearance, it is essential that clear
and precise messages are passed to the pilots concerned and acknowledgements
obtained. The recommended phraseology appears in CAP 413. Further transmission may
be necessary to ascertain the intentions of the pilot.
9. Data Display
9.1 Pertinent air traffic data is normally displayed on flight progress strips. Instructions for
marking hand written strips appear in Appendix D. Procedures for data display methods
are described in MATS Part 2.
10.2 When two or more flights of different categories request clearance the flight with the
highest category shall be dealt with first. Flow control procedures are implemented and
actioned by the Central Flow Management Unit. A flow control priority will be allocated
automatically on receipt of a flight plan.
10A.2 A pilot's declaration of "MINIMUM FUEL" indicates that no further fuel diversion options
are available where the aircraft is committed to land at the pilot’s nominated aerodrome of
landing with not less than 'final reserve fuel'. However, “MINIMUM FUEL” RTF
phraseology is not universally used by every aircraft operator and pilot.
Note: Final reserve fuel is typically fuel for 30 minutes of flight for turbine powered aircraft or 45
minutes for piston powered aircraft. (EASA-OPS)
10A.3 Controllers are not required to provide priority to pilots of aircraft that have declared
"MINIMUM FUEL" or that have indicated that they are becoming short of fuel.
10A.4 Controllers shall respond to a pilot's declaration of “MINIMUM FUEL” by confirming the
estimated delay he can expect to receive expressed in minutes, or no delay, when the
pilot is en-route to, is joining, or is established in an airborne hold; or by expressing the
remaining track mileage from touchdown if the aircraft is being vectored to an approach
(SERA.11012(a)).
10A.5 At locations where EATs are not issued until the amount of delay reaches a particular
value, controllers must provide a general indication of the delay, based on the best
information available at that time (see ENR 1.9-4).
10A.6 Once in possession of either the estimated delay or remaining track mileage, the pilot will
determine whether or not he can continue to the aerodrome with or without declaring a
fuel emergency. Controllers shall keep pilots informed of any increase in delay or
increase in track mileage after the pilot's initial declaration of "MINIMUM FUEL" following
which the controller can expect the pilot to declare an emergency.
10A.7 Controllers shall respond to a pilot who has indicated that he is becoming short of fuel but
has not declared "MINIMUM FUEL", by confirming the estimated delay he can expect to
receive expressed in minutes, or no delay, when the pilot is en-route to, is joining, or is
established in an airborne hold; or by expressing the remaining track mileage from
touchdown if the aircraft is being vectored to an approach; then ask the pilot if he wishes
to declare an emergency.
10A.8 Pilots declaring an emergency should use the following RTF phraseology "MAYDAY,
MAYDAY, MAYDAY" or “MAYDAY, MAYDAY, MAYDAY FUEL” and controllers shall
provide such aircraft with flight priority category A (SERA.11012(b))).
Table 2:
}
Royal Flights
which have been notified by
C Flights carrying visiting
NOTAM/Temporary Supplement
Heads of State
Initial instrument flight tests conducted by the CAA Flight Examining Unit. (RTF
callsign “EXAM”)
10C.3 It should be noted that these categories are designed for use as a method of tactical
handling by ATC and not as flow control priorities. A list of status indicators to be inserted
in field 18 of the flight plan, associated with flow control priorities, can be found in the UK
AIP.
11.2 Details of flights passing from one UK FIR to another and not operating within controlled
or advisory airspace but which have passed an estimate for the FIR boundary or adjacent
reporting point are to be passed to the appropriate ACC whenever workload and
communications permit.
(3) Squawk;
(5) Level;
(7) Route;
(1) there are any subsequent changes in Flight Level, Squawk or route; or
11A.3 The phraseology to be used when telephoning estimate messages is shown in Appendix
E.
(4) While the aircraft is climbing or descending to a previously agreed level, provided
that the transferring controller has ensured that standard separation will exist
between the transferred aircraft and all others for the remainder of the climb or
descent.
12.3 The phrase “continue as cleared” is not to be used in response to an initial call from an
aircraft.
aircraft not having yet reached the stage of transfer of control shall not alter the clearance
without the approval of the transferring unit.
13.2 EATs are based on the landing rate and are calculated according to the traffic situation.
They are to be expressed as actual times (not as time intervals) and revised if the
situation changes. They are to be passed to aircraft well in advance and revised until the
aircraft has left the holding facility.
13.3 Approach Control procedures for passing EATs are described in Section 3 and those for
Area Control in Section 4.
13A.2 The expression “delay not determined” is not to be used when changing runways.
13A.3 Delays can be forecast with reasonable accuracy and EATs are to be passed to aircraft.
Table 3:
15A.3 Units with SSR should allocate a discrete code to the lead aircraft, all other aircraft should
normally be instructed to squawk ‘standby’. However, if the stream extends for 3 NM or
more, the last aircraft should also be allocated the same code. For longer streams, the
code should be allocated to intermediate aircraft as appropriate.
15A.4 All ATC instructions and clearances shall be addressed to the formation leader. The
formation leader is responsible for ensuring safe separation between aircraft comprising
the formation; for military aircraft this is known as ‘Military Accepts Responsibility for
Separation of Aircraft’ or MARSA.
15A.5 During all co-ordination, traffic information and handover messages, controllers shall:
(2) identify the full extent of any formation of more than 1 NM in length.
15B.2 Formation flights by military aircraft may take place in controlled airspace without NSF
approval subject to the normal airspace entry requirements, the general requirements and
procedures above, and the additional controlled airspace procedures specified below.
15B.3 Formations are to be considered non-RVSM compliant irrespective of the RVSM status of
the individual aircraft types.
15B.4 All aircraft in the formation will monitor the relevant ATC frequency.
15B.5 Prior to a formation entering CAS, controllers are to obtain confirmation on RT that all
aircraft in the formation are within the parameters as specified at paragraph 15A above. In
the event that formation leaders report that they are outside these parameters, controllers
shall instruct the formation to remain clear of controlled airspace and establish their
intentions.
15B.6 When a formation has been cleared to climb or descend in CAS, controllers are to obtain
confirmation that all elements of the formation have vacated the level in question before
ATC re-allocate the previously assigned level. Formation leaders should confirm when all
formation elements have reached the new assigned level.
15B.7 The formation leader will immediately inform ATC if the formation elements are unable to
maintain within the required parameters as specified at 15A.1. In such circumstances,
controllers shall establish the extent of the formation so that instructions and/or
information appropriate to the airspace classification and flight rules of the formation can
be provided. Where necessary, additional discrete SSR codes should be allocated to
individual aircraft.
15B.8 For IFR formations that are unable to maintain within the required parameters, the
formation leader remains responsible for separation between aircraft comprising the
formation until standard separation has been achieved between individual aircraft and
each aircraft has been identified and placed under service. Additionally, controllers shall:
(1) provide other IFR traffic with essential traffic information and instructions as
necessary.
(2) if practicable, establish standard separation minima between all aircraft in the
formation as soon as possible, using ATS surveillance systems if available. If normal
separation minima cannot be established, the aircraft shall be given as much
separation from each other as possible and the formation given directions to enable
it to leave controlled airspace by the shortest possible route.
15B.9 Civilian controllers shall only permit an IFR formation under their direct control to join up in
controlled airspace when one of the aircraft is in emergency and a formation join up is
essential. Military controllers have specific procedures for formation join up in controlled
airspace that take due consideration of the formation’s proximity to UARs and other
airspace users.
15C.2 However there may be occasions when formations flight plan as GAT and receive a
service from civil controllers.
15C.3 Military procedures require an aircraft in an emergency that needs to break away from a
formation, to squawk the emergency special purpose code. It is usual practice for a
military aircraft in an emergency to be followed by another element of the formation. In this
circumstance, the aircraft suffering the emergency will be instructed to squawk the
emergency special purpose code. If an accompanying aircraft is not already in close
formation with the emergency aircraft, it will be instructed to squawk a discrete code until it
has joined formation with the emergency aircraft. Where the lead aircraft in a formation is
the aircraft in an emergency, the formation will advise ATC of the new leader, who must
then be identified and allocated a discrete squawk.
15C.4 Standard UK military callsign procedures apply to UK formations. In instances where there
is any doubt, such as when working USAF or foreign aircraft whose callsign procedures
may be different, the suffix “flight” or “formation” is to be used to indicate on RTF and
landline that the call refers to a formation.
17.2 Aircraft, both military and civil, which have been allocated this status have an operational
requirement to maintain a specific track and level(s) or a particular route and level(s). It is
imperative that a NDS aircraft is not moved from its pre-planned flight path because this
could render it operationally ineffective. If, for any reason, it is anticipated that adequate
separation cannot be maintained between other aircraft and the NDS flight, controllers are
to seek co-ordination with the agency providing the service to the NDS aircraft.
(2) Activities that may require the issue of a Permission or an Exemption from the ANO
or Rules of the Air Regulations;
18.2 Controllers may become involved in arrangements for UAAs, which can take place in any
class of airspace. Approval and clearance for a UAA within controlled airspace rests with
the relevant airspace controlling authority. However, many UAAs, whether in or outside
controlled airspace, involve AR in co-ordination with the sponsor and other participants
and require notification of the event to the aviation community.
18.3 Early warning of all UAAs is essential if co-ordination and notification is to be completed in
good time by AR. Notice requirements and the responsibilities of sponsors of UAAs are
described in the UK AIP and AICs. AR notifies affected ATC units of airspace reservations
or temporary procedures, which have been agreed with participating agencies by means
of NOTAM and Airspace Co-ordination Notices. This initial dissemination may be
supplemented by, or transferred to, Temporary Operating Instructions or other locally
produced briefing material.
18.4 AR is responsible for the allocation of GAT flight priorities and NDS in addition to co-
ordinating CAS-T requirements, VVIP/special/calibration flights, air-to-air refuelling,
military deployments and exercises.
19.2 Pilots of controlled balloon flights are required to comply with the same rules that apply to
other aircraft and subject to normal clearances. In practice balloons are only able to
comply with instructions from an ATC unit for changes in level. It is anticipated, although
not mandatory, that clearance would be sought prior to take-off and would only rarely be
issued for flights in busy airspace. The minimum in-flight weather conditions by day are
those required for VFR in the relevant class of airspace. Balloon flights are not permitted
in Class A airspace.
19.3 Controllers are reminded that, subject to the provisions of MATS Part 1, Section 1,
Chapter 4, they should take into account the present and expected traffic situation when
considering requests for flight and should not hesitate to refuse a clearance if other traffic
is likely to be compromised. It is unlikely that balloons will be operating in wind speeds of
greater than 15 knots.
20.2 Generally, glider flying utilising lift from thermals and ridges involves a deviation from a
straight-line route and, depending on the meteorological conditions, can involve rapid
changes in the vertical plane. Flights by paragliders and hang gliders will, except when
ridge soaring, fly with the prevailing wind and flights of over four hours and in excess of
100 miles are regularly flown. Conventional gliders have a better performance and
frequently plan long cross country flights.
20.3 It is likely that most requests for clearance will come from radio equipped, conventional
gliders using thermals for cross country flying. However, controllers must decide whether
the particular glider operation is compatible with the traffic situation prevailing at the time.
If it is not possible to issue a clearance immediately, the pilot must be advised when the
clearance is likely to be granted.
20.4 As a general guide to performance, the following are typical height losses against track
miles flown for various types of gliders which are not influenced by thermals and
topography.
20.5 Further details of the handling of gliders operating VFR in Class D Airspace and their
integration with other VFR and IFR traffic are outlined in Section 1, Chapter 5. The same
chapter provides information on Letters of Agreement between ATC units and other
airspace users, including gliding operations. Details of glider operations in TRAs are
detailed in Section 4.
(1) Responding to a ‘Police Emergency’. The pilot of a police aircraft is likely to declare
a ‘Police Emergency’ in situations where an immediate response is required when
life is at immediate risk, or a serious crime or major incident is in progress.
(1) Flight Category A: authorised for use by aircraft which have declared a ‘Police
Emergency’;
(2) Flight Category B: normal operational priority. The operation will not wish to draw
attention to itself. The pilot will expect controllers to suggest a new altitude or minor
changes to the police flight operating area in the event that the flight would cause a
delay to other traffic;
(3) Flight Category Z: authorised for training, test and other flights involving police
aircraft.
(1) The radiotelephony callsign ‘POLICE’. The ICAO three-letter telephony designator is
‘UKP’.
(3) When on an operational flight, the two or three-digit identifier is to be suffixed with
the Flight Category letter, either ‘A’ or ‘B’ as appropriate, to highlight to the ATS
provider the priority status requested by the pilot, e.g. ‘POLICE 01A’. Flight
Category ‘Z’ is not utilised as a callsign suffix.
21.4 Police aircraft will select either Mode A0032 or other such SSR codes assigned to the
Police and promulgated in AIP unless receiving a service from an ATS Unit which require
a different setting to be assigned in accordance with their unit SSR allocation plan.
21.5 Certain police aviation operations may warrant special ATC co-ordination or handling
procedures, in which case aircraft operators may consider the need for a SFN.
(1) Flight Category A: applies to all HEMS flights on emergency operational tasks;
(2) Flight Category E: is authorised for use by an aircraft positioning for the purpose of
conducting HEMS duties, e.g. returning to its base after delivering a casualty to
hospital. It is afforded priority over normal flights;
(3) Flight Category Z: authorised for training, test and other flights involving HEMS
aircraft.
(1) The radiotelephony callsign ‘HELIMED’. The ICAO three-letter telephony designator
is ‘HLE’.
(2) A two-digit individual aircraft identifier allocated to each HEMS aircraft by the CAA.
(3) When on a flight that is afforded priority, the two digit identifier is to be suffixed with
the Flight Category letter, either ‘A’ or ‘E’ as appropriate, to highlight to the ATS
provider the priority status requested by the pilot, e.g. ‘HELIMED 01A’. Flight
Category ‘Z’ is not utilised as a callsign suffix.
22.4 On routine operational tasks, training or other flights, no suffix letter will be appended, e.g.
‘HELIMED 01’.
23.2 Mareva injunctions relating to aircraft are likely to specify the aircraft registration rather
than a particular callsign. Upon receipt of such a Mareva injunction, ATS providers should
establish whether they are in communication with the aircraft in question.
Where an aircraft subject to a Mareva injunction is being provided with an ATS, controllers
should inform the pilot:
“You are subject to a Court Order prohibiting your aircraft from leaving the United
Kingdom, what are your intentions?”.
23.3 Controllers must not take any actions that would be detrimental to flight safety;
consequently, ATS should continue to be provided as normal, even in the event that the
pilot continues his flight. It should be noted that Mareva injunctions are relevant to
international flight and that aircraft subject to such an injunction could be flying legitimately
on an internal flight with no intention of leaving the UK territorial boundaries.
23.4 ATS providers should promulgate, as considered necessary, local procedures dealing with
the circumstances of a Mareva injunction being served. In developing such local
procedures, ATS providers should also consider taking legal advice as required in order to
ensure that the procedures are consistent with legal obligations in relation to the
injunction.
SECTION 1: CHAPTER 5
1. Introduction
1.1 This Chapter provides advice and guidance to controllers on the safe integration of VFR
flights with the IFR traffic flow within Class D CTA CTR/TMA.
2. Flight Rules
2.1 The pilot is responsible for determining the flight rules (VFR or IFR) under which he
wishes to conduct his flight, taking into account the prevailing flight meteorological
conditions, airspace classification, and the limitations of his licence/qualifications. Within
Class D airspace ground visibility is used for aircraft taking off from or approaching to land
at aerodromes, or entering the aerodrome traffic zone, or aerodrome traffic circuit,
whereas flight visibility is used for transiting aircraft. Controllers, therefore, must not
declare control zones to be ‘IFR’ or ‘IMC’.
3.2 Instructions issued to VFR flights in Class D airspace are mandatory. These may
comprise routeing instructions, visual holding instructions, level restrictions, and
information on collision hazards, in order to establish a safe, orderly and expeditious flow
of traffic and to provide for the effective management of overall ATC workload.
3.3 Routeing instructions may be issued which will reduce or eliminate points of conflict with
other flights, such as final approach tracks and circuit areas, with a consequent reduction
in the workload associated with passing extensive traffic information. VRPs may be
established to assist in the definition of frequently utilised routes and the avoidance of
instrument approach and departure tracks. Where controllers require VFR aircraft to hold
at a specific point pending further clearance, this is to be explicitly stated to the pilot.
28 December 2017 Section 1: Chapter 5: Integration of VFR Flights with IFR Traffic in Class D CTR/CTA/TMA - Page 1
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3.4 When issuing instructions to VFR flights, controllers should be aware of the overriding
requirements for the pilot to remain in VMC, to avoid obstacles and to remain within the
privileges of his licence. This may result in the pilot requesting an alternative clearance,
particularly in marginal weather conditions.
3.5 Approach radar controllers in particular should exercise extreme caution in vectoring VFR
flights – a geographical routeing instruction is preferable. Prior to vectoring, the controller
must establish with the pilot the need to report if headings issued are not acceptable due
to the requirements to remain in VMC, avoid obstacles, and comply with the low flying
rules. Controllers should be aware that pilots of some VFR flights may not be sufficiently
experienced to comply accurately with vectors, or to recover to visual navigation after
vectoring.
5. Letters of Agreement
5.1 ATCUs may establish Letters of Agreement with adjacent aerodromes or airspace users
to permit the integrated operation of airspace activities including glider, hang-glider,
parachuting and other activities. Letters of Agreement shall specify airspace sharing and
delegation arrangements, hours of operation and any necessary inter-unit co-ordination
arrangements.
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SECTION 1: CHAPTER 6
1. Services
(2) vectoring;
1A.2 Before a controller provides any of the above services he shall either:
(1) identify the aircraft, using a method appropriate to the surveillance system in use; or
(2) have had the identity of the aircraft transferred from another controller. The act of
identifying an aircraft does not imply that a service is being given.
1A.3 Surveillance systems may also be used to provide the following, whether or not the
aircraft has been identified:
(3) Information about observed weather for pilots and other controllers; and
1A.4 Surveillance services shall be provided to the maximum extent practicable to cover the
operational requirement subject only to workload, communications or equipment
capability.
1A.5 Regardless of the type of airspace, or the air traffic service being provided, nothing shall
prevent a controller from taking action he considers appropriate if he believes a risk of
collision exists.
Table 1:
(2) entering controlled airspace, except when entering controlled airspace in connection
with an IFR flight holding in Class E airspace in accordance with paragraph 1B.4
below;
(3) changing from IFR to VFR or VFR to IFR within Class E airspace;
(4) VFR flights entering Class B-D airspace from Class E airspace, or VFR flights
leaving Class B-D airspace to enter Class E airspace;
(a) unless pilots are provided with advance notice in accordance with paragraph
1B.3 below; or
(b) except when leaving controlled airspace in connection with an IFR flight holding
in Class E airspace in accordance with paragraph 1B.4 below.
1B.3 For flights leaving controlled airspace controllers should provide pilots with advance notice
of:
(1) the lateral or vertical point at which the aircraft will leave controlled airspace. Such
notice should be provided between 5-10 nm or 3000-6000 ft prior to the boundary of
controlled airspace;
(2) the type of ATS that will subsequently be provided, unless the aircraft is coordinated
and transferred to another ATS unit before crossing the boundary of controlled
airspace.
1B.4 IFR airborne holding might not be fully contained within the lateral boundaries of Class E
airspace. Controllers are not required to advise pilots of such flights on the changes of
ATS provided as they leave or enter Class E airspace. However, the controller shall
provide either a Deconfliction Service, or Procedural Service, depending on the availability
of ATS surveillance, for the portion of IFR flight in Class G airspace. Controllers are only
required to advise pilots when a Procedureal Service will be provided as pilots assume,
unless otherwise advised, that the type of UK FIS they will receive will be a Deconfliction
Service.
(1) IFR,
(2) pilots of aircraft operating Special VFR or VFR will comply unless they advise the
controller otherwise.
Note: The manner in which VFR flights under Radar Control Service may be safely integrated
with the IFR traffic flow in the vicinity of aerodromes is described in Section 3.
1C.3 Before an aircraft enters controlled airspace the controller must establish which flight rules
the pilot will be operating under.
1C.4 Before a Radar Control Service to IFR flights is terminated procedural separation must be
applied, except at ACCs when an aircraft will be entering an adjacent sector and:
1C.5 Participating VFR flights in Class E airspace shall not be provided with an Air Traffic
Control Service, but one of the following types of UK FIS in accordance with Section 1,
Chapter 12:
2.2 Controllers at these independent units are responsible for separating aircraft under their
control from all other aircraft in that controlled airspace.
(2) one or more changes of heading of at least 30°‚ as instructed by another controller;
(3) one or more changes of heading of at least 30° reported by the pilot.
3A.2 A turn for identification does not constitute the provision of a surveillance service.
However, controllers should take into consideration, terrain, other surveillance returns,
PSR coverage and the RoA before instructing an aircraft to alter heading.
(1) verify that the movements of not more than one Position Indication correspond with
those of the aircraft;
(2) exercise caution particularly when employing this method in areas where changes of
aircraft heading are commonly made as a navigational routine.
3B.2 Particular care should be taken to avoid confusion with aircraft overflying the aerodrome,
making a missed approach, departing from an adjacent runway or holding overhead the
aerodrome.
(1) over an exact reporting point which is displayed on the situation display; or
(2) at a particular distance not exceeding 30 miles on a particular radial from a co-
located VOR/DME or TACAN (DME). The source facility must be displayed on the
situation display; or
(3) over a notified visual reference point or prominent geographical feature, in either
case approved for the purpose and displayed on the situation display, provided that
the flight is operating with visual reference to the surface and at a height of 3000 ft
or less above the surface.
3C.2 The identification must follow a period of track observation sufficient to enable the
controller to compare the movement of the Position Indication with the pilot’s reported
route. The reported position and level of the aircraft must indicate that it is within known
PSR cover.
3C.3 This method must be reinforced by an alternative method if there is any doubt about the
identification because of:
(2) inaccurate reporting from aircraft at high level or some distance from navigational
facilities.
3C.4 A pilot is to be informed as soon as his aircraft has been identified. When operating inside
controlled airspace, the pilot of an aircraft need only be so informed if the identification is
achieved by the turn method.
4. SSR – Mode A
4A. Identification
4A.1 When using Mode A to identify aircraft, one of the following methods is to be employed:
(1) Observing the pilot’s compliance with the instruction to select a discrete four digit
code;
(2) Recognising a validated four digit code previously assigned to an aircraft callsign.
When code/callsign conversion procedures are in use and the code/callsign pairing
can be confirmed, the callsign displayed in the data block may be used to establish
and maintain identity;
4A.2 Caution must be exercised when employing this method because simultaneous requests
for SPI transmissions within the same area may result in misidentification. Aircraft
displaying the conspicuity code 7000 are not to be identified by this method.
(a) domestic codes which are assigned to aircraft flying within the areas of
responsibility of a unit;
(b) ORCAM codes which are assigned to international flights and will normally be
retained beyond the area of responsibility of the assigning unit.
(1) Instructing the aircraft to squawk the assigned code and observing that the correct
numbers appear on the situation display;
(2) Instructing the aircraft to “squawk IDENT” and simultaneously checking the code
numbers associated with the SSR response;
(3) Matching an already identified Position Indication with the assigned code for the
flight.
4C.3 If the code readout does not correspond to that assigned, the pilot is to be instructed to
reset the assigned code (SERA.13005(c)(1)). Where this fails to achieve display of the
assigned code then the pilot is to be instructed to select code 0000. If a corrupt code still
exists the pilot should normally be instructed to switch off the transponder
(SERA.13005(c)(2)). However, the corrupt code may be retained to assist identification
and tracking provided the Mode C has been verified. Associated ATC units are to be
informed of the retention of corrupt data.
(2) the controller has been notified that the code is corrupt.
(2) Code 1000, to indicate an aircraft conducting IFR flight as GAT, where the
downlinked aircraft identification is validated as matching the aircraft identification
entered in the flight plan;
(3) Code 2000 which is selected by pilots of aircraft entering the UK from an adjacent
FIR where the operation of transponders has not been required;
(4) Code 7007, which is selected by aircraft engaged on airborne observation flights
under the terms of the Treaty on Open Skies. Flight Priority Category B status has
been granted for such flights and details will be published by NOTAM.
(2) they are transponding on one of the special purpose codes or on one of the other
specific conspicuity codes assigned in accordance with the Code Assignment Plan;
(3) they are flying below 3000 feet in the aerodrome traffic pattern and have been
instructed to select the aerodrome traffic pattern conspicuity code (7010); or
(4) on grounds of safety the aircraft has been instructed to squawk standby. In view of
the associated reduction in protection from ACAS, such circumstances are to be
regarded as exceptional. ATSUs shall log the circumstances and duration of any
such occurrences. Records are to be made available to the CAA on request.
4F.2 In addition to those listed below, the SSR Code Assignment Plan provides a complete set
of UK conspicuity codes, including those used at specific units or locations.
Table 2:
5. SSR–Mode S
5A. Introduction
5A.1 There are two levels of Mode S: Elementary and Enhanced. Elementary Mode S provides
selective interrogation of aircraft, and the aircraft identification Down-Linked Airborne
Parameter (DAP). Enhanced Mode S enables further DAPs from an aircraft’s flight
management system, which include:
(2) IAS;
5A.2 In addition to traditional Mode A/C capabilities, Mode S transponder equipped aircraft
engaged in international civil aviation also incorporate an Aircraft Identification Feature
(sometimes referred to as Flight Identity or Flight ID). Flight crew of aircraft equipped with
a Mode S Aircraft Identification Feature will set the aircraft identification in the
transponder. The Aircraft Identification Feature should not be confused with the “aircraft
address” which is a unique ICAO code relating directly to the airframe in which the Mode
S transponder had been installed and over which crews have no control.
5B. Identification
5B.1 Direct recognition of the Aircraft Identification Feature on the situation display may be
used to establish surveillance identification, subject to either:
(1) correlation of the Aircraft Identification Feature with the aircraft identification entered
in the flight plan and displayed to controllers on flight progress strips; or
(2) correlation of the Aircraft Identification Feature with the aircraft’s callsign used in a
directed RTF transmission to the controller. However, controllers shall exercise
particular caution when there are aircraft with similar callsigns on the frequency, and
shall utilise an alternative method if they have any doubt about the surveillance
identification.
5B.2 Whenever it is observed on the situation display that the down-linked Aircraft Identification
Feature is different from that expected from the aircraft, the pilot shall be requested to
confirm and, if necessary, re- enter the Aircraft Identification Feature.
5B.3 If the discrepancy continues to exist following confirmation by the pilot that the correct
aircraft identification has been set in the Aircraft Identification Feature, the controller shall
take the following minimum actions:
(3) notify the erroneous Aircraft Identification Feature transmitted by the aircraft to the
next control position or unit.
5B.4 Transfer of identification using the Mode S Aircraft Identification Feature relies on both
units having appropriate Mode S surveillance capability; therefore, it shall only be
conducted in accordance with locally agreed arrangements and specified in MATS Part 2.
5C.2 Selected Altitude data will be presented as either a flight level or an altitude, depending on
local surveillance system settings, which are to be detailed in MATS Part 2. For ATC and
RTF purposes, the generic phrase ‘Selected Level’ is used to encompass data presented
as either an altitude or a flight level.
5C.3 Selected Levels display intent-based information only and shall not be used for the
purposes of separation.
5C.4 There are occasions where, whilst the flight crew have correctly interpreted the ATC
instruction, the Selected Level will be at variance. These situations will vary according to
aircraft type, aircraft operator, and mode of operation, but may include the following:
(1) SID/STARs with vertical restrictions, where pilots may select the final cleared level,
and utilise the aircraft flight management system to achieve the vertical constraints;
(2) Final approach, at which point pilots may pre-select the missed approach procedure
altitude;
(3) When the aircraft is being flown manually, in particular in response to vertical
avoiding action manoeuvres.
5C.5 Units equipped with Enhanced Mode S surveillance systems that enable DAPs should
display Selected Levels on the situation display as a means of mitigating the risk of level
busts. The checking of Selected Levels shall not be used as a substitute for RT read-back
of level clearances.
5C.6 Where the Selected Level is seen to be at variance with an ATC clearance, controllers
shall not state on RT the incorrect level as observed on the situation display. However,
taking into account the limitations of Selected Levels detailed above, controllers may
query the discrepancy using the following phraseology:
5C.7 Downlinked Mode S Barometric Pressure Setting data has the potential to assist in the
prevention of level busts. Where such data is available to a controller and a discrepancy is
observed between the QNH passed and that selected by the pilot, a controller should
query the discrepancy, using the following phraseology:
“(Callsign), check altimeter setting QNH 1000” (where QNH 1000 is the correct value).
6.2 A TMZ may be established for overriding safety reasons, where the airspace classification
would not ordinarily require aircraft to carry a transponder. The pilot of an aircraft that
wishes to operate in a TMZ without such serviceable transponder equipment may be
granted access to the TMZ subject to specific ATC approval. Procedures pertinent to each
TMZ shall be promulgated, which specify detailed access and notification requirements.
6.3 Within a TMZ, standard ATC procedures and separation/deconfliction minima, appropriate
to the airspace classification, are to be applied.
7. Transfer of Identity
7.1 If only PSR is available, a controller may transfer the identity of an aircraft to another
controller by any of the following methods:
(1) Direct designation (pointing) of the Position Indication where two situation displays
are adjacent or a conference type of display is used. If the information on two
situation displays is derived from separate PSR heads (or beams, if using a stack
beam system) the transferring controller must ensure that the blips on both displays
correlate before using this method. If parallax is likely to cause an error, an
alternative method is to be used;
(2) Designation of the Position Indication in terms of a direction and distance from a
common reference point (geographical position or navigational facility) accurately
indicated on both displays. The Position Indication, as seen by the accepting
controller, must be within 3 miles of the position stated. The distance between the
aircraft and the reference point must not exceed:
(a) 30 miles, if the aircraft is flying along a published ATS route or direction is given
as a bearing in degrees;
8. Lost Identity
8.1 Except as described in paragraph 8.2 below, a pilot shall be advised whenever
identification is lost.
8.2 When using SSR, controllers may be temporarily unable to read the data blocks
associated with aircraft due to overlapping or garbling e.g. in holding areas. Although this
constitutes a loss of identification, the pilot need not be advised that identification has
been lost if the controller anticipates that identification will be re-established immediately
the overlapping or garbling ceases.
(4) When an aircraft estimate differs significantly from the controller’s estimate based on
ATS surveillance system observation;
(5) When the pilot is instructed to resume his own navigation following vectoring, if
considered necessary by the controller.
9.3 Additionally, controllers may pass position information to aircraft whenever they consider it
necessary.
Table 3:
(1) A well known geographical position;Bearing (using points of the compass) and
distance from a known position;
(2) Magnetic track and distance to a location displayed on the situation display that is a
reporting point, an en route navigational aid, or an approach aid;
(3) Latitude and Longitude (by specific units only when authorised in MATS Part 2); or
10A.2 Vertical separation using Mode C is not applied against aircraft transponding A0000.
10A.3 Minimum vertical separation may be applied between verified Mode C transponding
aircraft provided the intentions of both aircraft are known to a controller because either:
10A.4 Aircraft Under Radar Control Service. If the intentions of Mode C transponding aircraft
are not known:
(1) the minimum separation for IFR flights in Class A-D airspace, and VFR flights in
Class B/C airspace, must be increased to 5000 feet; or alternative approved minima
within MATS Part 2; and
(2) unverified Mode C data may be used for separation purposes provided a minimum
vertical separation of 5,000 feet, or alternative approved minima within MATS Part 2,
in Class A-D airspace is Class A-D airspace is maintained. Radar returns, however
presented, are not allowed to merge;
(3) in Class E airspace radar returns, however presented, are not allowed to merge
unless the pilot in receipt of traffic information advises that he intends to avoid the
other aircraft without ATC assistance.
10A.5 Aircraft Under Deconfliction Service. If the intentions of the Mode C transponding aircraft
are not known, the vertical deconfliction minima must be increased to 3000 ft, and unless
the SSR Mode 3A indicates that the Mode C data has been verified, the surveillance
returns, however presented, should not merge.
10B.2 Verification may be achieved with the assistance of an ATSU with which the aircraft is in
contact.
10B.3 A Mode C readout can be assumed to have been verified if it is associated with a deemed
validated Mode A code (SERA.13010(b)).
10B.4 There is no requirement to monitor level readouts when Mode C information is not being
used to provide vertical separation. However, if a controller observes a discrepancy the
pilot is to be asked to confirm his altimeter setting and level. If the discrepancy remains,
the pilot is to be instructed to switch-off Mode C. If independent switching of Mode C is not
possible the pilot is to be instructed to select A0000.
(1) An aircraft may be considered to be at an assigned level provided that the Mode C
readout indicates 200 feet or less from that level;
(2) An aircraft which is known to have been instructed to climb or descend may be
considered to have left a level when the Mode C readout indicates a change of 400
feet or more from that level and is continuing in the anticipated direction;
(4) An aircraft may be considered to have reached an assigned level when three
successive Mode C readouts indicate 200 feet or less from that level.
10C.2 Mode C information is normally displayed as a Flight Level but on some ground
equipment the vertical position of an aircraft flying below a pre- determined datum is
displayed as an altitude.
(2) the identity has been transferred to the accepting controller, or has been established
by him; and
(3) the accepting controller is informed of any level or vectoring instructions applicable
to the aircraft at the stage of transfer.
11.2 If the route of the aircraft is not known the offering controller is to pass the observed track
or reported aircraft heading to the accepting controller.
(2) Details of all conflicting aircraft are passed to the approach radar controller;
(3) Conflicting aircraft are either transferred to Approach Radar Control or identified
according to the accepting controller’s decision;
(4) Neither the track nor the level of the conflicting aircraft is altered without co-
ordination.
13. Vectoring
13A. Responsibility
13A.1 A controller may instruct an aircraft to turn in any direction as dictated by circumstances
but when avoiding unknown aircraft the Rules of the Air should be observed if practicable.
13A.2 Aircraft flying outside controlled airspace and aircraft flying VFR within Class E airspace
are not obliged to follow instructions given by ATC, but where the pilot of an aircraft
accepts a Traffic Service or Deconfliction Service, the controller can expect that his
instructions will be followed.
13A.3 Unless an aircraft has planned to leave controlled airspace, it is not to be vectored outside
the horizontal or vertical limits, except:
(1) when an emergency situation arises requiring the aircraft to be vectored outside
controlled airspace;
(2) when avoiding severe weather; the circumstances must be explained to the pilot
before the aircraft leaves controlled airspace;
13A.4 Although IFR flights within class A-D airspace, and VFR flights within B/C airspace, are
deemed to be separated from unknown aircraft flying in adjoining uncontrolled airspace,
controllers should aim to keep the aircraft under their control at least two miles within the
13A.5 When vectoring is complete, pilots will be instructed to resume their own navigation.
Where a direct route is required, the controller shall specify this in the instruction.
14A.2 Controllers have no responsibility for the terrain clearance of, and shall not assign levels
to, aircraft operating Special VFR or VFR within controlled airspace which accept vectors.
Table 4:
Within 30 miles of the radar (2) 15 miles ahead and 20° either side of the
antenna associated with the unit aircraft’s track.
providing the service.
When the aircraft is within 15 miles of the antenna, and
provided an SMAC or approved procedure has been notified,
the 5 miles in (1) and the 15 miles in (2) may be reduced to 3
and 10 miles respectively.
Outside the phases above (2) within 30 miles of the aircraft (for all other
flights).
15.2 The action to be taken by controllers when they observe an unknown aircraft, which they
consider to be in unsafe proximity to traffic under their control, in various types of airspace
is as follows:
Table 5:
Class D IFR flights shall be given traffic avoidance advice and traffic information
shall be passed.
VFR and SVFR flights shall be given traffic information and if requested,
traffic avoidance advice; see note 1.
Pass traffic information unless the controller’s primary function of
sequencing and separating IFR flights is likely to be compromised.
IFR flights shall be given traffic avoidance advice whenever requested by
the pilot.
IFR flights shall be given traffic avoidance advice if radar derived or other
Class E information indicates that an aircraft is lost or has experienced a radio
failure.
Participating VFR flights shall:
(i) under a Traffic Service, be given traffic information.
(ii) under a Basic Service, be given traffic information as far as
practicable.
Participating IFR flights shall be given traffic information and traffic
avoidance advice if requested.
Class F
Participating VFR flights shall be given traffic information, as far as
practicable.
Under a Deconfliction Service, pass traffic information followed by traffic
Class G avoidance advice; see note 2.
Under a Traffic Service, pass traffic information.
Note 1: When providing traffic avoiding advice, controllers shall remind pilots of their responsibility
to remain clear of cloud with the surface in sight.
Note 2: When the controller considers that more immediate action is required by the pilot, traffic
avoidance advice may be passed by ATC before traffic information.
15.3 When traffic avoidance advice is issued to an IFR aircraft under a Radar Control Service,
controllers must seek to achieve the required minima and pilots must comply with the
instructions given. However when avoiding action is issued to an IFR aircraft under a
Radar Control Service in Class D or E airspace, and the pilot reports that he has the
unknown aircraft in sight and has positively stated that he will maintain his own separation
from it, further controller action may then be limited to passing traffic information. It is
recognised that it may not always be possible for controllers to achieve the required
separation minima against unknown traffic infringing controlled airspace due to the
potential for their sudden appearance and/or unpredictable manoeuvres; however,
controllers shall apply all reasonable endeavours (SERA.7002(a)).
15.4 When traffic avoidance advice is issued on request to VFR/SVFR aircraft under Radar
Control Service, controllers are not required to achieve separation minima. Such avoiding
action instructions shall be aimed at ensuring that the risk of collision is reduced as far as
possible subject to aircraft proximity and aircraft constraints. Pilot compliance is subject to
prevailing meteorological conditions (SERA.7002(a)).
15.5 Controllers shall advise pilots when the conflict no longer exists (SERA.7002(b)).
15.6 Controllers who observe that an aircraft using an assigned SSR code is, or is about to,
make an unauthorized infringement of their airspace should attempt to contact the
relevant agency to identify the aircraft and agree a course of action.
15A.2 When the subject aircraft is on the controller’s frequency, the controller must ensure that
identification of the aircraft is then achieved.
15A.3 Controllers should note that simple transfers of communication form part of the London
FISOs’ standard operating procedures. However, FISOs are not permitted to issue any
control instructions to aircraft. Controllers must not request FISOs to relay any
instructions, other than for the aircraft to transfer directly to their control frequency so that
the controller can resolve the situation.
15A.4 Procedures for Royal Flights in fixed-wing aircraft are detailed in Chapter 9.
(1) Bearing from the aircraft in terms of the 12-hour clock (when the aircraft is turning,
direction of the unknown aircraft by compass points);
(3) Direction in which the unknown aircraft is proceeding, e.g. “traffic is opposite
direction/crossing left to right”, etc.
(4) Height information when available, this may include the unverified Mode C of
unknown aircraft.
Under some circumstances, controllers may consider it prudent to inform a pilot of other
traffic which is separated from his aircraft. In such cases, to prevent any possible
confusion, no reference should be made to the actual level of the other aircraft. If
necessary, the pilot should be informed that the other aircraft is “(number) thousand feet
above/below”.
17.2 When weather is observed on the situation display, or is known to be present, pilots
should be advised of the weather’s location and, if known, intensity and direction of
movement.
17.3 When a pilot requests an alternative heading or route for weather avoidance, controllers
shall accommodate such requests, taking into account the prevailing traffic situation.
When a pilot’s request cannot be accommodated, controllers shall offer an alternative
weather avoidance clearance or explain to the pilot why his request cannot be met.
17.4 When weather avoidance will take an aircraft outside controlled airspace the pilot must be
informed of this and offered an appropriate service. Pilots routeing outside controlled
airspace for weather avoidance should be issued a clearance to rejoin as required.
17.5 If a pilot is cleared to follow his own navigation, or accepts a heading, in order to avoid
weather, he should be requested to report when able to accept vectors back on-track.
18A. Introduction
18A.1 There are many potential causes of spurious primary returns (‘clutter’), including: weather;
anomalous propagation; ground/sea returns; birds; wind turbine effects; and radar
countermeasures such as chaff. Whilst it may be possible for some forms of clutter to be
distinguishable from aircraft surveillance returns, this may not always be possible,
especially where processed surveillance systems are employed.
18A.2 Clutter on the situation display has the potential to impact on ATS provision in the
following ways:
(2) Aircraft position symbols, track histories, data blocks may be hidden or obscured.
(3) Spurious track(s) may be generated, which may be indistinguishable from genuine
aircraft returns.
(4) There may be in delay in aircraft being identified and placed under an ATS.
18A.3 The impacts listed above are likely to affect the degree, accuracy and timeliness of the
instructions, advice, and information that controllers are able to provide to pilots, with
consequent impacts on safety and expedition. Additionally, the existence of clutter may
necessitate aircraft being rerouted, or air traffic services reduced below the level
requested by the pilot. Specific tactical procedures to be applied by controllers in
response to clutter observed on the situation display are provided below.
18A.4 In addition to observable clutter, wind turbines have the potential to generate a variety of
other negative effects on ATS systems and these should be considered by ATS providers
when participating in the wind turbine application planning process. CAP764 (CAA Policy
and Guidelines on Wind Turbines) provides specific information.
18A.5 Where clutter of a long term or permanent nature is generated in a particular area, in
addition to the procedures, the potential impacts and mitigations should be assessed
locally and procedures documented in MATS Part 2.
(1) For aircraft in receipt of a Deconfliction Service or Traffic Service, controllers should
inform the pilot of the extent of the clutter and where practicable offer a reroute.
However, this may not be possible due to traffic density, airspace availability and/or
the requirement to follow specific arrival or departure tracks. The extent of such a
reroute should where possible aim to achieve the planned lateral deconfliction
minima from the observed clutter. However, it may still be necessary to reduce
traffic information, and if applicable deconfliction advice, from the direction of the
clutter as detailed at Section 1 Chapter 12.
(2) For aircraft in receipt of a Traffic Service, and those aircraft under a Deconfliction
Service that are not rerouted as above, controllers shall inform pilots of a reduction
in traffic information/deconfliction advice as detailed at Section 1, Chapter 12. If the
controller cannot maintain aircraft identity, the service shall be terminated.
(3) For all surveillance services, in order to maintain track identity of aircraft being
vectored to final approach, if re-routing around the clutter is not practicable for the
reasons specified above, an alternative type of approach may need to be
conducted.
(1) The controller may vector the aircraft around the clutter; however, this might not be
practicable due to traffic density, airspace availability and/or the requirement to
follow specific arrival or departure tracks.
(2) If the intensity of the clutter is such that the controller is not able to clearly see the
aircraft’s PSR or SSR position symbol, radar separation shall not be used to
separate it and other controlled aircraft.
(3) The controller may provide IFR traffic in Class E airspace with reduced traffic
information.
18C.2 In the event of clutter being present on the situational display, VFR flights receiving a
Traffic Service within Class E airspace shall be managed in accordance with 18B.1(1) and
18B.1(2) above.
18C.3 The controller remains responsible for providing advice and information on aircraft that are
considered to be infringing controlled airspace. Therefore, the controller should consider
the nature and consistency of the clutter including any observed movement, relative
speed and track, and take appropriate action if it is considered to be an unknown aircraft.
(1) a radar approach is not possible owing to clutter, in which case the controller shall
inform the aircraft; or
(2) a radar approach could be carried out, but there may be a possibility of radar
contact being lost. In this case the controller shall inform the aircraft as early as
possible that clutter is affecting his display and that missed approach instructions
will be passed in good time if it becomes necessary to abandon the approach.
separation is employed, pilots shall be informed and essential traffic information passed
as necessary.
20.2 When a previously failed surveillance system is notified as being serviceable, before any
ATS surveillance service is provided the controller shall re-identify all aircraft by an
approved method in accordance with the procedures described in this Chapter.
20.3 When approved by the CAA, procedures which obviate the need for controllers to be
notified that the ATS surveillance system has been returned to a serviceable state shall be
detailed in MATS Part 2.
SECTION 1: CHAPTER 7
1. Units of Pressure
1.1 Hectopascals are the notified units for the measurements of pressure for flying within UK
airspace. Pilots are normally expected to carry out their own conversion from
Hectopascals to inches of mercury if this is necessary and controllers will only provide
pressure settings in inches of mercury when specifically requested by an individual
aircraft. A conversion table can be found in Appendix A.
3. Pressure Setting
3.1 A correctly calibrated pressure altimeter when set to:
(2) QFE altimeter setting will indicate height above the reference datum.
3.2 Both of these settings are rounded down to the nearest whole Hectopascal before being
passed to the pilot. However, they are given to the nearest tenth of a Hectopascal if
requested.
4.2 The values which are made available hourly for the period H + 1 to H + 2, are given in
whole Hectopascals.
4.3 ATSUs are to have available the Regional Pressure Setting for the ASR in which they are
situated and appropriate adjacent regions. These values are to be passed to pilots when
requested or at the discretion of the controller. However, a pressure setting shall not be
volunteered if a controller is uncertain that it is appropriate to the flight.
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4.4 Airspace below TMAs and CTAs listed in the UK AIP at ENR 1-7-2 does not form part of
the ASR Regional Pressure Setting system. Instead, the QNH of an adjacent aerodrome
should be used for aircraft at or below the Transition Altitude.
5. Transition
(1) Within controlled airspace by the controlling authority and it will normally be based
on the QNH of the major aerodrome;
(2) Outside controlled airspace by the Aerodrome Operator and based on the
aerodrome QNH.
6. Vertical Position
6.1 A pilot normally assesses the vertical position of his aircraft above obstacles by using an
accurately set altimeter. It is imperative, therefore, that controllers always issue the correct
pressure setting and that they check the read-back from the pilot.
6.2 When transmitting altimeter pressure settings that are lower than 1000 hPa, controllers
are to specify clearly the unit of measurement and pay particular attention to the read-
back.
6.3 The table below shows the altimeter subscale settings, the terms in which vertical position
is reported and the occasions on which they are used to report to ATSUs
(SERA.8015(eb)(1),(3),(4)&(5)).
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Table 1:
Subscale Expressed in
When used to report vertical position to ATSUs
Setting terms of
(1) At, or above, the transition level.
Note: When an aircraft has been cleared to climb from an altitude to a Flight Level, vertical
position will be reported in terms of Flight Level, unless intermediate altitude reports have
been specifically requested by ATC. Similarly when a pilot is descending from a Flight
Level to an altitude, the pilot will change to the aerodrome QNH unless further Flight Level
vacating reports have been requested by ATC, in which case the QNH will be set
following the final Flight Level vacating report.
7. Procedures at Aerodromes
7A.2 The pressure settings associated with aerodrome and threshold elevation are expressed
as QFE aerodrome and QFE threshold respectively. QFE threshold for an instrument
runway is used when the threshold elevation is 7 feet or more below aerodrome elevation.
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7C.2 When an aircraft is cleared to descend from a Flight Level to an altitude the appropriate
QNH shall be included in the same transmission. If Flight Level vacating reports are
required, the request should be included with the descent clearance.
7C.3 The Transition Level must be passed to the pilot in due time prior to his aircraft reaching it
during descent (SERA.8015(eb)(2)), either by voice communications, ATIS broadcast or
data link (GM1 SERA.8015(eb)(2)).
7C.4 After QNH is assumed to have been set by an aircraft all reference to vertical position
shall be in terms of altitude. Vacating reports, which have not been requested at the time
of the descent clearance, may be in terms of altitude, particularly if the aircraft has only
one altimeter.
7C.5 Aircraft are to be given the appropriate QNH prior to commencing an approach.
7C.6 Aerodrome and threshold elevations are to be available upon request. Alternatively, when
requested by the pilot, or local procedures require, the appropriate QFE shall be given.
7C.7 After a missed approach, vertical position is referred to in terms of altitude. It may be
necessary, therefore, to include QNH with the subsequent clearance.
7C.8 Additional altimeter setting procedures for Approach Radar are described in Section 3.
8.2 The lowest cruising level available for assignment shall be determined at the ACC using
the appropriate Regional Pressure Setting. On an airway this must always be at least 500
feet above the notified base.
8.3 Unit procedures for the determination and use of the first available Flight Level above the
transition altitude shall be described in MATS Part 2.
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separation from aircraft operating beneath the base of controlled airspace. Similarly,
controllers should exercise caution when operating close to the upper vertical limit of a
control zone or area where it is not contiguous with further controlled airspace.
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SECTION 1: CHAPTER 8
Diversion Procedures
1. Introduction
1.1 Aircraft may divert from their planned destination to another aerodrome on the initiative of
the pilot or as requested by the appropriate authority on the ground.
(1) When the weather at the planned destination is reported to be below the minima
prescribed by an Aircraft Operator for their aircraft;
(2) When obstructions on the landing area, which constitute a hazard to aircraft landing,
cannot be cleared within a reasonable period;
(4) The failure of essential ground aids to landing in circumstances which would require
their use;
1.3 The Aerodrome Operator is responsible for decisions regarding the availability of the
aerodrome.
2.2 When specifically requested by the pilot that his company or a nominated addressee be
advised of his diversion the controller is to pass this message to the ATSU at either:
3.2 In cases of emergency it may be necessary for an aircraft to be diverted without prior
consultation with the Aircraft Operator. In this event, the controller shall pass the message
to the pilot expressed as a request and inform the Aircraft Operator as soon as possible.
When the operator of the aircraft is not known, the pilot is to be asked to nominate an
addressee.
4. Action by Pilot
4.1 On receipt of the diversion message the pilot will acknowledge and comply with the
request or give his reason for non-compliance. If he decides against diversion, permission
to attempt a landing shall not be refused unless the aerodrome has been closed by the
Aerodrome Operator.
6.2 Aircraft from the CIS, even though in an emergency, must not be diverted to RAF
aerodromes except with the agreement of D&D.
6.3 In all other cases of emergency, controllers should, whenever possible, consult D&D
before arranging for the aircraft to land at an RAF or USAF aerodrome. RAF aerodromes
that intend to keep open beyond the hours of watch published in the RAF En Route
Supplement British Isles and North Atlantic will notify D&D. This information will be
available to the civil supervisor if required.
SECTION 1: CHAPTER 9
Royal Flights
1. Introduction
1.1 A Royal Flight within UK airspace is defined as the movement of an aircraft specifically
tasked to carry one or more members of The Royal Family afforded such status by the
Head of Royal Travel, The Royal Household.
1.2 Flights within UK airspace by members of other Royal Families, other reigning
Sovereigns, Prime Ministers and Heads of State of Commonwealth and foreign countries,
may also be afforded Royal Flight status by the CAA.
2A.2 CAS-T will be notified as Class D airspace; applicable access criteria and separation
standards apply.
2A.3 CAS-T of appropriate height/width bands, and levels, will be established to encompass
any portion of the track and flight level of the Royal aircraft, which lies outside of
permanent Class A, C and D airspace. Temporary control zones and control areas will be
established around all aerodromes used for the departure or arrival of a Royal Flight.
2A.4 Regardless of the prevailing meteorological conditions, aircraft shall only fly within CAS-T
when an ATC clearance has been obtained from the controlling authorities specified as
follows:
(1) Temporary Control Zones. Class D temporary control zones will be established
around aerodromes of departure and destination where no permanent control zones
exist. Control zones for Royal Flights will extend between a 5 and 10 NM radius
from the centre of the aerodrome from ground level to an upper level designated for
each Royal Flight dependent upon the Royal aircraft type and the aerodrome’s
surrounding airspace. The control zone will be established for a period (for outbound
flights) of 15 minutes before, until 30 minutes after, the ETD of the Royal aircraft or
(for inbound flights) for a period of 15 minutes before, until 30 minutes after, the ETA
of the Royal aircraft at the aerodrome concerned. Overall control of these control
(2) Temporary Control Areas. Class D temporary control areas, dimensions and
duration thereof, will be established to meet the specific requirements of a Royal
Flight. The controlling authority will be the appropriate civil or military ACC.
(3) Permanent Control Zones and Areas. The controlling authority will be the
designated controlling authority for the permanent zone or area and the duration will
be as laid down in sub-paragraphs (1) and (2) above. Where an aerodrome has its
own control zone, then the requirement to establish a temporary control zone of the
dimensions specified in sub-paragraph (1) above may be waived.
2A.5 A temporary control zone, area or airway may be cancelled at the discretion of the military
Commander or civil ATC Supervisor, as appropriate, when the Royal aircraft has left the
temporary zone, area or airway and is established en route in permanent Class A, C or D
airspace, or has landed.
2A.6 Training flights, including parachute training flights, by any member of The Royal Family,
which are planned and carried out under VFR or IFR, and under the control of an ATS
surveillance service unit, will normally be classified as Royal Flights. CAS-T, where
required, will be established as agreed by the aircraft operating organisation and the CAA.
2B.2 The provision of a supplementary service is determined by the civil ACC; AR informs
LATCC (Mil) of the requirements. If notification of a Royal Flight is received at such a time
that headquarters staff would not be able to make the arrangements during office hours,
e.g. a signal received 1900 hours on Friday for a flight on Sunday, the Watch Supervisor
at the civil ACC of the FIR in which the flight originates shall, in consultation with LATCC
(Mil), ensure that a supplementary radar service is provided.
4. Diversions
4.1 The operational control of Royal aircraft of No. 32 (The Royal) Squadron is vested in the
RAF and diversions must be authorised by D&D. The pilot, however, retains authority to
deviate from flight plan if he thinks it necessary. The operational control of civilian
chartered aircraft being used for a Royal Flight remains with the company and diversions
will be arranged in accordance with normal civil practices.
SECTION 1: CHAPTER 10
1. Introduction
1.1 Airborne Collision Avoidance System (ACAS) is an aircraft system based on SSR
transponder signals, which operates independently of ground- based equipment to
provide advice to the pilot on potential conflicting aircraft that are equipped with SSR
transponders.
1.2 All civil turbine-engine aircraft having a maximum take-off mass (MTOM) exceeding 5700
kg or a maximum approved seating configuration of more than 19 are mandated to carry
and operate ICAO SARPs-compliant Airborne Collision Avoidance System (ACAS)
equipment. The only equipment currently able to meet the ACAS II mandate requirements
is the Traffic Alert and Collision Avoidance System II (TCAS II) software version 7. Certain
military transport-type aircraft may also be TCAS II equipped. Civil registered historical
and ex-military turbine-engine aircraft are exempted from this requirement.
1.3 Aircraft Operators experiencing ACAS equipment failure may request permission to
operate in UK airspace for up to 10 days in accordance with current TCAS II Minimum
Equipment List provisions. Due to the safety benefits arising from TCAS operations and
the collaborative way in which it arrives at collision avoidance solutions, any aeroplane
with an unserviceable transponder as well as an unserviceable TCAS will not be permitted
in UK airspace for which mandatory carriage of a transponder is required.
1.4 The carriage and use of TCAS II acts only as a safety net, and does not in any way alter
the respective responsibilities of pilots and controllers for the safe operation of aircraft.
2.2 Warnings for aircraft equipped with TCAS II are given in two steps:
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Table 1:
2.3 If a conflicting aircraft is not reporting altitude, a TA may be given, but not an RA.
2.4 RAs will be presented only if the conflicting aircraft is transponding on Mode C or Mode S.
Where both aircraft in an encounter are fitted with TCAS II, the transponders will
communicate with each other to agree complementary Resolution Advisories. If the
conflicting aircraft is not transponding, no warnings are given.
2.5 TCAS II is programmed to take account of the host aircraft’s performance characteristics
and level when issuing RAs.
4. Nuisance Advisories
4.1 TAs and RAs may occur even though standard separation exists. Therefore, a controller
should not immediately assume that separation has been lost, or that he is at fault, when
a pilot reports they are manoeuvring in response to an RA.
4.2 One cause of an unnecessary RA is high vertical speed, particularly at low level and in
congested airspace. Pilots have been asked to avoid these manoeuvres, particularly in
the final stages of climb or descent, unless they are justified, for example, a request to
expedite a climb, emergency descent etc.
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4.3 It has been reported that ground testing of transponder equipment may generate
advisories in TCAS II-equipped aircraft. CAP 562 Civil Aircraft Airworthiness Information
and Procedures, provides general guidance to aircraft maintenance organisations on
precautions to be considered when ground testing transponder equipment.
5.2 When a pilot reports a TCAS RA, controllers shall not attempt to modify the aircraft’s flight
path or reiterate previously issued instructions, until the pilot reports “Clear of Conflict”.
(SERA.11014(c))
5.3 Once an aircraft departs from an ATC clearance in compliance with an RA, or a pilot
reports an RA, the controller ceases to be responsible for providing separation between
that aircraft and any other aircraft affected as a direct consequence of the manoeuvre
induced by the RA. The controller shall resume responsibility for providing separation for
all the aircraft affected when:
(1) The controller acknowledges a report from the flight crew that the aircraft has
resumed the current clearance; or
(2) The controller acknowledges a report from the flight crew that the aircraft is
resuming the current clearance and issues an alternative clearance which is
acknowledged by the flight crew. (SERA.11014(d))
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6. TCAS Phraseology
6.1 Specific ICAO TCAS phraseology has been adopted. The phraseology is clear, simple,
concise and to the maximum extent devoid of ambiguity and potential to cause operational
confusion. This phraseology provides:
(1) the means to ensure that the pilot and controller have, wherever possible, a clear
mutual understanding of the progression of an RA manoeuvre; and
(2) the means to delineate the point at which the responsibility for the separation of
aircraft directly affected by the manoeuvre is transferred from the controller to the
pilot and, at the completion of the manoeuvre, from the pilot back to the controller.
6.2 There is no requirement for the pilot to notify the controller prior to responding to an RA.
There are four cases for which communication is necessary between pilot and controller;
the phraseology to be used is reproduced below.
Notification after a flight crew starts to deviate from any ATC clearance or instruction to
comply with a RA:
Notification after the RA response is completed and a return to the ATC clearance or
instruction is initiated:
Notification after the response to a RA is completed and the assigned ATC clearance or
instruction has been resumed:
7. Controller Reporting
7.1 A holder of an Air Traffic Controller’s licence or Flight Information Service Officer’s licence
is to report, within 72 hours, any occurrence which has, or if not corrected would have,
endangered an aircraft, its occupants, or any other person. The ANO and CAP 382
contain guidance on what is a reportable occurrence but ultimately the individual officer
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involved will have to use his own judgment to assess whether the incident as a whole
meets the requirements for mandatory reporting.
7.2 All ACAS RAs are required to be reported under the MOR scheme. If there is good reason
to believe that the appropriate details of the occurrence have already been, or will be,
reported under the MOR scheme by someone else (e.g. UK airline or pilot), there is no
need to file a duplicate report.
7.3 The filing of the report does not absolve the controller from additionally reporting an
AIRPROX or other report about the same incident, according to the circumstances.
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SECTION 1: CHAPTER 11
1. Traffic Information
1.1 Traffic information passed between ATS personnel is information about aircraft that is
relevant to the provision of an air traffic service. The purpose of traffic information is to
enable the recipient to determine whether or not any action is necessary to achieve or
maintain the required separation between the subject aircraft. For example, after receiving
traffic information, a controller may consider it necessary to issue avoiding action or may
request co-ordination with respect to the traffic.
1.2 The passing of traffic information does not imply a commitment to an agreed course of
action and there is no undertaking to update the information that has been passed. The
dynamic nature of an air traffic environment may render traffic information obsolete once
passed but if, after receiving traffic information, a controller believes that co-ordination is
necessary, he shall use the term “request co-ordination” and shall follow the verbal
procedure detailed below.
2. Co-ordination
2.1 Co-ordination is the act of negotiation between two or more parties each vested with the
authority to make executive decisions appropriate to the task being discharged. Co-
ordination is effected when the parties concerned, on the basis of known intelligence,
agree a course of action. Responsibility for obtaining the agreement and for ensuring
implementation of the agreed course of action may be vested in one of the controllers
involved.
2.2 Controllers should be aware that co-ordination between the parties involved can be upon
aircraft that are either in receipt of, or about to be in receipt of, an air traffic service.
2.3 A controller may carry out co-ordination on behalf of another controller, provided that the
traffic situation and time available are such that the controller being represented can put
into effect any agreed actions.
(1) Tactical Co-ordination. The co-ordination of individual aircraft to which the co-
ordinating controllers are providing, or are about to provide, an ATS. It is achieved
either verbally (face-to-face or over a landline) or silently using an electronic data
communications system. Silent co-ordination procedures are to be detailed in the
MATS Part 2 and Unit Military Procedures.
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2.5 When approved by the CAA, co-ordination is deemed to have been achieved if an
estimate message has been passed and the accepting ATC unit has raised no objection.
(1) make verbal contact with the appropriate controller and, after identifying himself,
open the dialogue with the words “Request Co-ordination”;
(2) refer to his aircraft and the aircraft upon which co-ordination is requested in the
order most appropriate to the situation;
(3) propose a course of action upon which agreement is requested and obtain a clear
decision on that proposal. To ensure clarity and avoid misunderstandings, before
terminating the call, parties shall explicitly state the action required of their aircraft to
achieve the agreed course of action. For example, an appropriate response to a
request for an aircraft to maintain FL120 may be, “My traffic maintaining FL120”. A
response that does not reaffirm the details of the agreement, such as “Roger”, is not
acceptable.
3.2 When co-ordinating aircraft that are or are about to be operating within RVSM designated
airspace, the RVSM approval status of the individual aircraft involved shall be included in
the co-ordination message, unless the status is known to be self evident to both
controllers.
3.3 The proposed course of action to achieve separation must be expressed in unambiguous
terms. A statement that no action will be taken can constitute an agreement, although
there is still a requirement for both controllers to state explicitly the actions required of
their aircraft.
4.2 Where aircraft are climbing or descending, controllers may include the provision of
horizontal separation until a flight profile is achieved that will provide adequate vertical
separation with the conflicting traffic. For example, “I will take 5 miles until above FL210”,
or, “I will take 5 miles until 1000 ft above/below on Charlie”. In the absence of an RT
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report from the pilot of passing or reaching the required level, the criteria for level
assessment of Mode C shall be applied. Where combinations of horizontal and vertical
separation are used in co-ordinating aircraft, controllers shall closely monitor aircraft
tracks and levels to ensure that standard horizontal separation is maintained until the
requisite vertical separation exists.
4.3 Where both aircraft are climbing, or both are descending, controllers may co-ordinate to
use Mode C indications to enable an expeditious step climb/descent, which maintains the
required vertical separation/ deconfliction minima, e.g. “I will take 1000 ft above/below on
Charlie”, or, “I will maintain 1000ft above/below on Charlie”. In such circumstances the
criteria for level assessment of Mode C shall be applied.
5.2 For IFR/VFR flights within Class F/G airspace, controllers are individually responsible for
deciding whether they need tactical co-ordination, and to initiate such requests as
appropriate. Therefore, unless specified in MATS Part 2, controllers should not rely on
other controllers to initiate tactical co-ordination.
5.4 Traffic Service. Unless safety is likely to be compromised, a pilot receiving a Traffic
Service shall not change level, route, manoeuvring area, or deviate from an ATC heading
without first advising and obtaining a response from the controller. Consequently, such
aircraft may be co-ordinated in the vertical plane, and in the lateral plane for those aircraft
that have been allocated an ATC heading, without recourse to the pilot, For manoeuvring
aircraft and aircraft following a route, co-ordination in the lateral plane may take place
subject to the controller agreeing with the pilot the precise horizontal limits of the aircraft’s
manoeuvres.
5.5 Basic Service. Unless the pilot has entered into an agreement with a controller to
maintain a specific course of action, a pilot receiving a Basic Service may change level,
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heading, or route without advising the controller. Consequently, prior to such aircraft being
coordinated in either the vertical or lateral planes, the following conditions shall be met:
(1) The aircraft receiving the Basic Service is subject to identification, and it is expected
that identity will be maintained throughout the period during which co- ordination is
requested.
(2) The pilot receiving a Basic Service agrees to maintain the required vertical or lateral
profile for the required period or distance.
(3) For manoeuvring aircraft and aircraft following a route, co-ordination in the lateral
plane may take place subject to the controller agreeing with the pilot the precise
horizontal limits of the aircraft’s manoeuvres.
6. Penetration of Airspace
6.1 Aircraft receiving an ATS from an ATC unit must not be permitted to penetrate the
airspace of another unit unless prior co-ordination has taken place. The responsibility for
initiating co-ordination rests with the controller of the unit transferring control. The
transferring controller must comply with any conditions specified by the accepting
controller.
6.2 Certain CAA approved units are permitted to operate within controlled airspace without
prior co-ordination.
7. Approval Request
7.1 If the first reporting point after take-off is in the adjoining area an approval request must be
made to that ACC and co-ordination achieved before clearance is given to the aircraft
unless the requirement has been waived by the CAA.
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SECTION 1: CHAPTER 12
1A. Introduction
1A.1 It is essential that the UK FIS Principles are read in conjunction with the specific type of
FIS as they underpin and apply equally across this suite of services.
1B.2 UK FIS provision is constrained by the nature of this uncontrolled airspace environment
within which pilots of known and unknown flights may make unexpected manoeuvres.
Consequently, controller workload cannot be reliably predicted.
Note 1: The parameters that govern the extent to which controllers pass traffic information and
deconfliction instructions or advice to assist pilots in discharging their responsibility for
collision avoidance are specified below and in the CAP 774. Terrain clearance
requirements and restrictions regarding heading instruction and level allocation are also
specified.
Note 2: The provision of the UK FIS, and associated deconfliction of flights in Class F/G airspace,
is predicated on flight rules. Deconfliction Service and Procedural Service are only
available to aircraft operating under IFR.
pilots operating outside controlled airspace are not mandatory; however, the all users rely
upon compliance with the specified terms and conditions so as to promote a safer
operating environment for all airspace users.
1F. Agreements
1F.1 Agreements can be established between a controller and a pilot on a short-term tactical
basis, such that the operation of an aircraft is laterally or vertically restricted beyond the
core terms of the Basic Service or Traffic Service. This is for the purposes of co-ordination
and to facilitate safe interaction with other airspace users with more stringent deconfliction
requirements. In agreeing to a course of action, pilots will take into account their
responsibilities as defined under the Rules of the Air, including that for terrain clearance.
Unless safety is likely to be compromised, a pilot shall not deviate from an agreement
without first advising and obtaining a response from the controller. Controllers shall
remove restrictions as soon as it is safe to do so.
Note 1: Agreements may be made which restrict aircraft to a specific level, level band, heading,
route, or operating area.
Note 2: Controllers should be aware that not all requests for an agreement will be accepted and
they should try to take account of the pilot’s operating requirements whenever possible.
Consequently, controllers should avoid excessive or unnecessary use of agreements and
be prepared to act accordingly if an agreement is not achieved.
(1) Controllers at approved ATC Units that do not have surveillance equipment
available will routinely apply Procedural Service to aircraft carrying out IFR holding,
approach and/or departure procedures;
(2) Where ATC are unable to provide the full range of UK FIS to aircraft after they leave
controlled airspace, a controller should specify the types of UK FIS that are available
in advance in accordance with Section 1, Chapter 6, paragraph 1B.3.
local procedures to be promulgated that are at variance to CAP 774, these will be subject
to regulatory approval.
Note: By incorporating elements of another type of UK FIS to that agreed, there is a danger that
pilots will come to routinely expect those elements as a part of that service provision. This
could lead to pilots requesting an inappropriate type of UK FIS for the flight profile or flight
conditions in the future. Therefore, pilots should not expect, nor ask, controllers to provide
any element of another type of UK FIS. Controllers shall not offer nor provide elements of
any other type of UK FIS.
2. Basic Service
2A. Definition
2A.1 Basic Service is a type of UK FIS provided for the purpose of giving advice and
information useful for the safe and efficient conduct of flights. This may include weather
information, changes of serviceability of facilities, conditions at aerodromes, general
airspace activity information, and any other information likely to affect safety. The
avoidance of other traffic is solely the pilot’s responsibility.
2B. Provision
2B.1 Controllers and FISOs may provide Basic Service. Controllers may utilise ATS
surveillance system derived information in the provision of a Basic Service.
2D. Identification
2D.1 A controller may identify an aircraft to facilitate co-ordination or to assist in the provision of
generic navigational assistance, but is not required to inform the pilot that identification
has taken place.
Note: Identification of an aircraft in receipt of Basic Service does not imply that a different type of
UK FIS is being provided or that any subsequent monitoring will take place. Controllers
may allocate SSR codes to aircraft in receipt of Basic Service. The issuance of such a
code does not constitute the provision of a surveillance related service.
2E.2 However, where a controller has information that indicates that there is aerial activity in a
particular location that may affect a flight, they should provide information in general terms
to assist with the pilot’s situational awareness. This will not normally be updated by the
controller unless the situation has changed markedly, or requested by the pilot.
2E.3 Controllers with access to surveillance-derived information shall avoid the routine
provision of traffic information on specific aircraft but may use that information to provide a
more detailed warning to the pilot if they perceive a significant proximity hazard.
2E.4 If a controller notices that a definite risk of collision exists, a warning shall be issued to the
pilot. ((EU) 923/2012 SERA.9001 and SERA.9005(b)(2))
Note: Information relating to collision hazards includes only known activities that constitute risks
to the aircraft concerned. The availability of such information to air traffic services may
sometimes be incomplete (e.g. limitations in radar or radio coverage, optional radio
contact by pilots, limitations in the accuracy of reported information by pilots, or
unconfirmed level of information) and, therefore, air traffic services cannot assume
responsibility for its issuance at all times or for its accuracy. (GM1 SERA.9005(b)(2))
2E.5 Whether traffic information has been provided or not, the pilot remains responsible for
collision avoidance without assistance from the controller
2F. Deconfliction
2F.1 Deconfliction is not provided under Basic service. If a pilot requires deconfliction advice,
Deconfliction Service will be requested. A controller shall make all reasonable endeavours
to accommodate such a request as soon as practical.
2G. Terrain
2G.1 Basic Service is available at all levels and the pilot remains responsible for terrain
clearance at all times. Agreements may be made with pilots to fly at any level, without any
requirement for a reminder of terrain clearance responsibility to be passed to the pilot.
2H. Headings
2H.1 Unless the pilot has entered into an agreement with a controller to maintain a specific
course of action, a pilot may change heading or routeing without advising the controller.
Other than for the purposes of identification, a controller shall not issue specific heading
Note: Generic navigational assistance may include information relative to the position of
significant navigational features and information on routeings as requested by the pilot. If
the controller has access to an a surveillance system and has the capacity, he may
facilitate the provision of generic navigational assistance by identifying the aircraft and
providing suggested track information. Additionally, bearings utilising direction finding
equipment, i.e. QDM/QTE, may be provided subject to ATC equipment capability.
Alternative routeings may be suggested to assist the pilot in remaining clear of notified
airspace reservations etc, e.g. “Suggest re-route to the west to remain clear of active
danger area”.
2J. Levels
2J.1 Unless the pilot has entered into an agreement with a controller to maintain a specific
level or level band, a pilot may change level without advising the controller.
3. Traffic Service
3A. Definition
3A.1 Traffic Service is a surveillance-based type of UK FIS where, in addition to the provisions
of Basic Service, the controller provides specific surveillance-derived traffic information to
assist the pilot in avoiding other traffic. Controllers may provide headings and/or levels for
the purposes of positioning and/or sequencing; however, the controller is not required to
achieve deconfliction minima, and the pilot remains responsible for collision avoidance.
3B. Provision
3B.1 A Traffic Service shall only be provided by a controller with access to an appropriate
surveillance system.
3D. Identification
3D.1 The controller shall identify the aircraft, inform the pilot that he is identified, and maintain
identity. If identity is lost the pilot shall be informed and the controller shall attempt to re-
establish identity as soon as practical.
Note 1: Traffic is normally considered to be relevant when, in the judgement of the controller, the
conflicting aircraft’s observed trajectory indicates that it will pass within 3 NM and, where
level information is available, 3,000 ft of the aircraft in receipt of the Traffic Service or its
level-band if manoeuvring within a level block. However, controllers may also use their
judgment to decide on occasions when such traffic is not relevant, e.g. passing behind or
within the parameters but diverging. Controllers shall aim to pass information on relevant
traffic before the conflicting aircraft is within 5 NM, in order to help the pilot meet his
collision avoidance responsibilities and to allow time for an update in traffic information if
considered necessary.
Note 2: Good judgement is essential to ensure that traffic information is relevant and timely.
Controllers should take account of the aircraft's relative speeds, lateral and vertical
closure rates, and track histories.
Note 3: Distances displayed on ATS surveillance systems can be at variance to the actual
distances between aircraft due to limitations inherent to surveillance systems. Some
aircraft may not be displayed at all.
3F. Deconfliction
3F.1 Deconfliction is not provided under Traffic Service. If a pilot requires deconfliction advice,
Deconfliction Service will be requested. The controller shall make all reasonable
endeavours to accommodate this request as soon as practical.
Note: When providing headings/levels for the purpose of positioning and/or sequencing or as
navigational assistance, the controller should take into account traffic in the immediate
vicinity based on the aircraft's relative speeds and closure rates, so that a risk of collision
is not knowingly introduced by the instructions passed. However, the controller is not
required to achieve defined deconfliction minima and pilots remain responsible for
collision avoidance even when being provided with headings/levels by ATC.
3G. Terrain
3G.1 Subject to surveillance system coverage, Traffic Service may be provided below ATC unit
terrain safe levels; however, pilots remain responsible for terrain clearance at all times.
Other than when following a notified instrument flight procedure, pilots intending to
descend below the ATC unit terrain safe level shall be reminded by controllers that they
remain responsible for terrain clearance.
3H. Headings
3H.1 A controller may provide headings for the purpose of positioning, sequencing, or as
navigational assistance.
3H.2 When operating under their own navigation, pilots may alter course as required; however,
unless safety is likely to be compromised, pilots will not change their general route or
manoeuvring area without first advising and obtaining a response from the controller.
3H.3 When following an ATC heading, unless safety is likely to be compromised, a pilot will not
change heading without first advising and obtaining a response from the controller as the
aircraft may be co-ordinated against other airspace users without reference to the pilot. If
an ATC heading instruction is unacceptable to the pilot he will advise the controller
immediately. Pilots remain responsible for collision avoidance even when in receipt of
ATC headings and will advise the controller in the event that they need to deviate from a
heading in order to comply with Rules of the Air with regard to collision avoidance, or for
any other reason. Controllers shall only give heading instructions when the aircraft is at or
above an ATC unit’s terrain safe level. However, if pilots request a heading to fly from the
controller whilst operating below the ATC unit terrain safe level, this may be provided as
long as the controller reminds the pilot that he remains responsible for terrain clearance.
3I. Levels
3I.1 Pilots may select their own operating levels or may be allocated levels to fly by the
controller for positioning and/or sequencing of traffic or for navigational assistance. If a
level is unacceptable to the pilot he will advise the controller immediately. Unless safety is
likely to be compromised, a pilot will not change level or level band without first advising
and obtaining a response from the controller, as the aircraft may be co-ordinated against
other airspace users without reference to the pilot. Pilots remain responsible for collision
avoidance, even when flying at a level allocated by ATC and will advise the controller in
the event that they need to deviate from a level in order to comply with the Rules of the Air
with regard to collision avoidance or for any other reason. Levels allocated by controllers
shall be terrain safe in accordance with the ATC unit terrain safe levels, unless:
(2) such levels form part of VFR clearances for aerodrome arrival; or
(3) to enter controlled airspace that by necessity require flight below the unit terrain safe
levels.
Note: In order to reduce RT loading and increase flexibility, pilots who require to frequently
change level whilst receiving Traffic Service will request a level 'block' to operate within.
4. Deconfliction Service
4A. Definition
4A.1 Deconfliction Service is a surveillance-based type of UK FIS where, in addition to the
provisions of Basic Service, the controller provides specific surveillance-derived traffic
information and allocates headings and/or levels to fly aimed at achieving planned
deconfliction minima, or for positioning and/or sequencing. Nevertheless, the avoidance of
other traffic remains the pilot’s responsibility.
4B. Provision
4B.1 Deconfliction Service shall only be provided by a controller with access to an appropriate
surveillance system.
Note: Pilots that do not require ATC deconfliction advice or deconfliction minima to be applied
will not request Deconfliction Service.
4D. Identification
4D.1 The controller shall identify the aircraft, inform the pilot that he is identified, and maintain
identity. If identity is lost, the pilot shall be informed and the controller shall attempt to re-
establish identity as soon as practical.
4F. Deconfliction
4F.1 A controller shall provide traffic information, accompanied with a heading and/or level
instruction aimed at achieving a planned deconfliction minima against all observed
conflicting aircraft in:
4F.2 Controllers are not required to provide deconfliction advice on aircraft within adjacent
controlled airspace (excepting active TRA/MTA) unless surveillance-derived or other
information indicates that such aircraft are leaving controlled airspace; however,
controllers may pass traffic information.
Note: Although active TRA and MTA are controlled airspace, autonomous flight is permitted and
UK FIS are available.
(2) 3,000 ft vertically and, unless the SSR code indicates that the Mode C data has
been verified, the surveillance returns, however presented, should not merge. (Note:
Mode C can be assumed to have been verified if it is associated with a deemed
validated Mode A code. The Mode C data of aircraft transponding code 0000 is not
to be utilised in assessing deconfliction minima).
4F.4 The deconfliction minima against aircraft that are being provided with an ATS by the same
controller, or that have been subject to co-ordination, are:
(2) 1,000 ft vertically; (2,000 ft within active MDA/MTA above FL410, and above FL290
where both aircraft are not RVSM approved); or
4F.5 High controller workload or RTF loading may reduce the ability of the controller to pass
deconfliction advice and the timeliness of such information. Furthermore, unknown aircraft
may make rapid and unpredictable manoeuvres. Consequently, it is recognised that
controllers cannot guarantee to achieve these deconfliction minima; however, they shall
apply all reasonable endeavours.
Note: In areas of high traffic density, Deconfliction Service may be provided, despite the
controller considering it unlikely that deconfliction minima will be achieved. In such
circumstances controllers should advise the pilot of reduced traffic information delivery
and that deconfliction minima may not be achieved.
4F.6 The pilot will inform the controller if he elects not to act on the controller’s deconfliction
advice. The pilot then accepts responsibility for initiating any subsequent collision
avoidance against that particular conflicting aircraft. However, the controller is not
prevented from passing further information in relation to the conflicting traffic, if in his
opinion it continues to constitute a definite hazard.
Note: Distances displayed on ATS surveillance systems can be at variance to the actual
distances between aircraft due to the inherent limitations of surveillance systems.
Consequently, lateral deconfliction minima may have to be greater than those specified
above, as detailed in a unit’s regulatory approval. Furthermore, some aircraft may not be
displayed at all by ATS surveillance systems.
4G. Terrain
4G.1 Deconfliction Service shall only be provided to aircraft operating at or above the ATC
unit’s terrain safe level, other than when a controller at an Approach Control unit provides
an ATS to aircraft on departure from an aerodrome and climbing to the ATC unit’s terrain
safe level, or to aircraft following notified instrument approach procedures. In all other
circumstances, if a pilot requests descent below ATC unit terrain safe levels, controllers
shall discontinue Deconfliction Service and, subject to surveillance and RTF coverage,
apply Traffic Service and inform the pilot. If an approach controller detects a confliction
when an aircraft is below the ATC unit terrain safe level whilst departing from an
aerodrome and climbing to the ATC unit terrain safe level, or when following notified
instrument approach procedures, traffic information without deconfliction advice shall be
passed. However, if the pilot requests deconfliction advice, or the controller considers that
a definite risk of collision exists, the controller shall immediately offer such advice as
follows:
(1) For aircraft on departure, controllers shall provide avoiding action advice and a
terrain warning.
(2) For aircraft conducting pilot interpreted instrument approaches, controllers shall
provide avoiding action advice and an associated terrain safe level to climb to or fly
at. It is assumed that conformity with such advice will necessitate repositioning.
(a) If the terrain safe area for the procedure is known to the controller or indicated
on the surveillance display, avoiding action may be passed without an
associated climb instruction, as long as the controller ensures that the aircraft
remains within the terrain safe area, and the turn instruction is such that the
controller considers that the approach can be continued without the need for
repositioning.
(b) If the controller anticipates that the avoiding action turn will result in flight
outside the terrain safe area or the approach not being able to be completed, a
terrain safe level to fly at will also be provided, and repositioning will be
necessary.
Note 1: When aircraft are in the initial stages of departure or on final approach, due to limited
aircraft manoeuvrability, controllers need to balance the safety impact of passing
deconfliction advice at these critical stages of flight against the risk of collision presented
by conflicting aircraft. Consequently, deconfliction minima do not apply in these
constrained circumstances and avoiding action is provided with the aim of preventing
collisions. Furthermore, controllers need to be aware of the high flight deck workload that
is likely to be present in the event of avoiding action being given which is at variance to
the published missed approach procedure being followed.
Note 2: The procedures regarding deconfliction advice to aircraft on initial departure and final
approach are designed to cater for ‘pop up’ conflictions over which the controller has no
advance warning due to the uncontrolled nature of Class G airspace. Controllers should
attempt to co-ordinate and deconflict observed traffic prior to allowing either the departure
of an aircraft that is expected to require Deconfliction Service, or the final approach of an
aircraft that is already receiving Deconfliction Service.
Note 3: Where aircraft are transferred to the Aerodrome Controller once established on final
instrument approach, ATC units should use internal ATC liaison processes to ensure that
warnings of conflicting traffic are passed in a timely fashion to the pilot.
4H. Headings
4H.1 A pilot may operate under his own navigation or a controller may provide headings to fly
for the purpose of positioning, sequencing, navigational assistance, or to achieve
deconfliction minima. If a heading instruction is unacceptable to the pilot he will advise the
controller immediately. Unless safety is likely to be compromised, a pilot will not alter
course without first obtaining approval from the controller, as the flight profile may have
been co-ordinated against other airspace users without reference to the pilot.
4I. Levels
4I.1 Controllers normally provide level allocations for positioning, sequencing, navigational
assistance, or to achieve deconfliction minima. If a level is unacceptable to the pilot, he
will advise the controller immediately. Unless safety is likely to be compromised, a pilot
will not change level without first obtaining approval from the controller, as an aircraft’s
flight profile may be co-ordinated against other airspace users without reference to the
pilot.
5. Procedural Service
5A. Definition
5A.1 Procedural Service is an ATS where, in addition to the provisions of Basic Service, the
controller provides restrictions, instructions, and approach clearances, which if complied
with, will achieve deconfliction minima against other aircraft participating in the Procedural
Service. Neither traffic information nor deconfliction advice can be passed with respect to
unknown traffic.
5B. Provision
5B.1 Procedural Service shall only be provided by controllers at ATC units with Regulatory
approval to provide such an ATS. Controllers at ATC units that do not have surveillance
information available may routinely apply Procedural Service to pilots of aircraft carrying
out IFR holding, approach and/or departure procedures without the need to first elicit the
pilots’ requirements.
Note 1: Not all ATC units are able to provide Procedural Service. However, Procedural Service is
most commonly available from ATC units without surveillance equipment that also have
notified IFR arrival, departure or en-route procedures.
Note 2: Subject to Regulatory approval, controllers at ATC units that are equipped with
surveillance equipment may provide Procedural Service. This is most frequently applied to
aircraft previously in receipt of a surveillance ATS where track identity may not be
maintained, or when surveillance equipment is not available.
5D. Identification
5D.1 Aircraft need not be identified in order for Procedural Service to be provided.
Note: Controllers may allocate a notified SSR conspicuity or special purpose codes to assist
adjacent surveillance equipped ATC units in ascertaining that the aircraft is in receipt of an
ATS from the particular ATS provider. The issuance of such a code does not constitute
the provision of a surveillance ATS.
5F. Deconfliction
5F.1 A controller shall aim to achieve deconfliction minima from other participating flights by
allocating levels, radials, tracks, routes and timings to fly, and by making use of pilot
position reports.
(3) those lateral and longitudinal criteria listed in Section 1 Chapter 3 as lateral and
longitudinal separation standards.
5F.3 High controller workload or RTF loading may reduce the ability of the controller to pass
deconfliction advice, and the timeliness of such information.
5F.4 In the event that an aircraft that requires Procedural Service makes contact with the
controller whilst already within the deconfliction minima, controllers shall pass essential
traffic information to all affected aircraft. In such circumstances, it is recognised that
controllers cannot guarantee to achieve deconfliction minima; however, they shall apply all
reasonable endeavours to do so as soon as practical.
5F.7 The pilot will inform the controller if he elects to refuse the controller’s deconfliction advice;
consequently that pilot accepts responsibility for initiating any subsequent avoidance
against the aircraft in question and any other aircraft affected. However, the controller is
not prevented from passing further information in relation to the conflicting traffic if in his
opinion it continues to constitute a definite hazard. Other traffic involved in such a
scenario shall be provided with traffic information and deconfliction advice as far as is
practical.
5F.8 Controllers may, subject to workload, initiate agreements with pilots of aircraft under Basic
Service to restrict their flight profile in order to co-ordinate them with aircraft in receipt of a
Procedural Service. Controllers shall limit the occasions on which they make such
agreements to those where it is clear that a confliction exists, and only when controller
workload permits.
5G. Terrain
5G.1 Procedural Service is available at all levels and the pilot remains wholly responsible for
terrain clearance at all times. However, if a pilot wishes to operate below ATC unit terrain
safe levels, unless on departure from an aerodrome when climbing to the ATC unit’s
terrain safe level, or when following notified instrument approach procedures, controllers
shall advise the pilot of the terrain safe level and remind him of his terrain responsibilities.
5I. Levels
5I.1 Controllers should allocate levels for positioning, sequencing, navigational assistance, or
to achieve deconfliction minima. If a level is unacceptable, the pilot will advise the
controller immediately. Unless safety is likely to be compromised, a pilot will not change
level without first obtaining approval from the controller, as an aircraft’s flight profile may
be co-ordinated against other airspace users without reference to the pilot.
Note 1: The requirement to provide ICAO Air Traffic Advisory Service is met through the provision
of Procedural Service or Deconfliction Service.
Note 2: Deconfliction Service enables the provision of surveillance-derived traffic information and
deconfliction advice on unknown aircraft, which are not available under Procedural
Service.
Note 3: There are occasions where, although it is not possible for Deconfliction Service to be
provided, surveillance-derived information may still be available. In such circumstances,
the provision of Traffic Service in addition to Procedural Service ensures that the
requirements of ICAO Air Traffic Advisory Service are met, whilst enabling traffic
information on unknown aircraft to be provided.
SECTION 1: CHAPTER 13
Speed Control
1. General
1.1 Controllers may request pilots to increase/decrease speed in order to facilitate a safe and
orderly flow of traffic. Speed adjustments should be limited to those necessary to establish
and/or maintain a desired separation/deconfliction minima or spacing and should not be
outside the speed ranges laid down in MATS Part 2. Pilots shall be advised when a speed
control restriction is no longer required.
1.3 At levels at or above FL280, speed adjustments for aircraft in the cruise should be
expressed in multiples of 0.01 Mach. At levels below FL280, speed adjustments should be
expressed in multiples of 10 kt based on indicated airspeed (IAS).
1.4 The application of speed control should be appropriate for the phase of flight, as its
application over a long period of time may affect aircraft fuel reserves, and can affect the
aircrew’s planned operating profile. Instructions involving frequent changes of speed
should be avoided.
1.5 Pilots will adhere to the speed (IAS or Mach Number) approved or assigned by ATC and
will request ATC approval before making any changes thereto. Pilots of aircraft unable to
maintain the approved or assigned speed (e.g. for aircraft performance reasons) will
inform ATC as soon as possible. In such circumstances, controllers shall apply an
alternative method to establish or maintain the desired separation/ deconfliction minima or
spacing between the aircraft concerned.
2.2 Instructions for an aircraft to simultaneously maintain a high rate of descent and reduce its
speed should be avoided. Where possible, aircraft should be allowed to descend at their
own preferred speed. Most operators have indicated that their preferred economical
descent profile is in the speed range 250 – 280 knots, with 270 knots being seen as a
good compromise where streaming is necessary.
2.3 Aircraft should not be instructed to operate at a high speed by one controller and, on
transfer to the next sector, be instructed to reduce speed significantly. Aircraft should be
transferred from en route to Approach control in the speed range of 250 kt - 300 kt IAS;
speeds outside this band should be co-ordinated with the receiving sector. Allocated
speeds should take into account speed limit points and target levels where published.
2.4 Controllers should endeavour to permit aircraft to operate in a clean configuration for as
long as circumstances permit. Arriving aircraft below FL150 should not be allocated a
speed of less than 210 kt (200 kt for propeller aircraft) unless within 20 track miles of the
runway threshold, at which point the speed may be reduced to between 150 and 180 kt. In
exceptional circumstances a pilot may be asked to reduce to ‘minimum approach speed’.
2.5 Speed control should not be applied to aircraft after passing a point 4 NM from the
threshold on final approach. Commercial aircraft operations require that an approach is
flown as a ‘Stabilised Approach’, in which an aircraft should be in its landing configuration
and at its final approach speed by at least 1000 feet above the threshold elevation. If
agreed by the aircraft operator this may be lowered to 500 feet; however, this is not to be
considered as normal operations. The higher the speed applied on final approach, the
greater the chance of an approach becoming unstable and a missed approach being
initiated.
3. Departing Aircraft
3.1 For departing aircraft the minimum speeds allocated should be:
SECTION 2: CHAPTER 1
Aerodrome Control
1. Provision of Services
1.1 An Aerodrome Control unit shall provide:
1.2 An Aerodrome Control unit provides services principally to aircraft flying with visual
reference to the surface in, and in the vicinity of, the ATZ and operating on the
manoeuvring area. It is normally a separate unit but may be combined, either temporarily
or permanently, with an Approach Control unit.
1.3 Unless MATS Part 2 permits otherwise, an aerodrome controller shall not provide
Approach Surveillance Services whilst engaged on Aerodrome Control duties.
2. Responsibilities
2.1 Aerodrome Control shall issue information and instructions to aircraft under its control to
achieve a safe, orderly and expeditious flow of air traffic with the objective of:
(a) aircraft flying in, and in the vicinity of, the ATZ;
(c) aircraft and vehicles, obstructions and other aircraft on the manoeuvring area.
Note: Aerodrome Control is not solely responsible for the prevention of collisions. Pilots and
vehicle drivers must also fulfil their own responsibilities in accordance with Rules of the
Air.
2.2 In order to execute his duties, an aerodrome controller has authority over aircraft,
vehicles and personnel on the manoeuvring area and aircraft moving on the apron.
2.3 Aerodrome Control may be divided into Air Control and Ground Movement Control.
Air Control shall provide services for (1)(a) and (1)(b) and has absolute authority over all
movements on active runways and their access points.
Ground Movement Control shall provide services for (1)(c) and (2) except on active
runways and their access points.
2.4 Clearance Delivery Officer (CDO) positions may be established at aerodromes to relay
ATC departure clearances with approved procedures detailed in MATS Part 2.
(2) Informing aircraft under its control of any depletion of the aerodrome emergency
services;
(3) Providing an Approach Control Service when carrying out functions delegated by
Approach Control;
(4) Supplying the following information to Approach Control and, according to unit
instructions, Approach Radar Control:
(a) Pertinent data on IFR, Special VFR and VFR traffic including departures,
missed approaches and overdue aircraft;
(5) Informing the Aerodrome Operator when it becomes apparent that there is a
deterioration in the state of the aerodrome or associated facilities for which the
Aerodrome Operator is responsible;
2A.2 Approach Control may instruct approaching IFR flights to contact Aerodrome Control
before transfer of control has become effective. Until approaching aircraft are flying with
visual reference to the surface, Aerodrome Control shall not issue any instructions or
advice which would reduce the separation established by Approach Control.
3. Co-ordination
3.1 Aerodrome Control shall co-ordinate with Approach Control:
(2) arriving aircraft which make their first call on the tower frequency (unless they are
transferred to Approach Control).
3.3 Approach Control may delegate the responsibility for co-ordination to Approach Radar
Control.
3.4 Aerodrome Control shall co-ordinate with adjacent aerodromes to ensure that the traffic
circuits do not conflict.
4. Transfer of Control
4.1 Unless specified otherwise in the MATS Part 2, the responsibility for control of a departing
aircraft shall be transferred from Aerodrome Control to Approach Control:
(1) in VMC: prior to the aircraft leaving the vicinity of the aerodrome, or prior to the
aircraft entering IMC;
5. Airspace Classification
5.1 In addition to the responsibilities described above, controllers are to provide minimum
services according to the classification of the airspace within which the aerodrome and
associated ATZ is located.
6A. Class D
6A.1 When the reported meteorological conditions at aerodromes in Class D airspace reduce
below a ground visibility of 5 km and/or a cloud ceiling of 1500 ft, both by day or night,
ATC shall advise pilots of aircraft intending to operate under VFR to or from such
aerodromes, and request the pilot to specify the type of clearance required.
6A.2 Except for helicopters using Police; Helimed; Rescue; Electricity; Grid; Powerline, or
Pipeline callsigns, or an SAR training flight operating in accordance with MATS Part 2,
controllers shall not issue any further VFR clearances to aircraft wishing to operate in
accordance with VFR to or from an aerodrome, or enter the aerodrome traffic zone, or
aerodrome traffic circuit, of an aerodrome within Class D airspace when the official
meteorological report at that aerodrome indicates, by day or night, a ground visibility less
than 5 km and/or a cloud ceiling less than 1500 ft (SERA.5005(b)(1)&(2)).
Note 1: UK General Permission ORS4 no. 1125 permits VFR flight within a control zone at night.
Note 2: UK General Exemption ORS4 no. 1195 enables the pilot in command of an aircraft to
transit Class D airspace in accordance eith VFR by day, remaining clear of cloud with
surface in sight and an indicated airspeed of 140 kt or less, with a flight visibility of 5 km or
for helicopters, a flight visibility of 1500 m. Except for commanders of a Powerline,
Pipeline, Police, Helimed, or SAR helicopters, which operate in accordance with their
respective ORS4, this exemption does not enable the pilot in command of an aircraft to
transit an aerodrome traffic zone or aerodrome traffic circuit within a control zone, when
the official meteorological report at that aerodrome indicates the values specified in
paragraph 6A.2.
Note 3: UK General Exemption ORS4 no. 1222 exempts operations of helicopters conducting
Powerline; Pipeline; Police; Helimed; Search and Rescue (SAR) flights, including SAR
training flights operating in accordance with a Letter of Agreement with the Air Traffic
Service Provider, from complying with SERA.5005(b) and SERA.5010(a) and (b).
Note 4: For the purpose of observing the meteorological conditions at an uncontrolled and/or
unlicensed aerodrome or operating site located within a control zone, and assessing
whether those conditions satisfy the minima specified in SERA.5005(b) and
SERA.5010(c) as appropriate, the Civil Aviation Authority deems the following to be
competent to act as ‘accredited observers’ as required within Regulation (EU) 923/2012
Article 2(82) for their flight:
(a) The holders of valid EASA Flight Crew Licences, valid National Flight Crew Licences
and Certificates issued by, or on behalf of, the United Kingdom Civil Aviation
Authority, and third country licences deemed valid in accordance with Article 150 of
the Air Navigation Order 2016; and
(b) A student pilot-in-command (SPIC) who has passed the theoretical knowledge
examination in meteorology toward the grant of an EASA Flight Crew Licence or
National Flight Crew Licence or Certificate issued by, or on behalf of, the United
Kingdom Civil Aviation Authority within the preceding two years.
6A.3 When the reported ground visibility consists of two values, the lower of the two values
shall be used when determining whether to implement the above procedures.
6A.4 Procedures for operations into subsidiary aerodromes will be found in MATS Part 2.
6B.2 Controllers shall advise pilots of the implementation and subsequent cancellation of LVP
at an aerodrome.
7. Information to Aircraft
(1) generic traffic information to enable VFR pilots to safely integrate their flight with
other aircraft;
(2) specific traffic information appropriate to the stage of flight and risk of collision;
(3) timely instructions as necessary to prevent collisions and to enable safe, orderly and
expeditious flight within and in the vicinity of the ATZ.
7A.2 MATS Part 2 shall detail local procedures for the integration of aircraft in the vicinity of the
aerodrome.
7A.3 Aircraft under the jurisdiction of Aerodrome Control and in receipt of information critical to
the continuing safe operation of the aircraft must be kept informed of any subsequent
changes. For example:
(3) Changes in the notified operational status of approach and landing aids.
(2) rough portions of the manoeuvring area and whether marked or not;
(3) failure or irregular functioning of the aerodrome lighting system. Defects must be
passed to pilots in the form that they have been reported to the controller.
Controllers should not make assumptions that a particular defect renders an
associated aid unserviceable or not available. The pilot is responsible for deciding
his course of action;
(5) aircraft parked close to the runways or taxiways and aircraft engaged in ground
running of engines;
(6) depth of snow layers on runways and taxiways, snow piled or drifted on the
manoeuvring area, melting snow and slush, rutted ice and snow;
(7) in snow and ice conditions: information concerning sweeping and/or sanding of
runways and taxiways;
(8) reports on the estimated braking action determined either by the equipment
described in Chapter 8 or by reports from pilots of aircraft, which have already
landed, including: a description of the prevailing conditions, e.g. standing water,
snow settling; the time of measurement; the type of aircraft if an aircraft report.
When the braking action has been reported as less than good and more than thirty
minutes has elapsed since the previous aircraft report or measurement, the braking
action should be checked before passing details to an aircraft.
The assessment of braking action by use of a brake testing decelerometer (e.g. the
Tapley Meter) is to be carried out solely in conditions of dry snow and ice, gritted or
ungritted;
(9) bird formations or individual large birds reported or observed on or above the
manoeuvring area or in the immediate vicinity of the aerodrome and the extent of
any bird dispersal action being carried out. When flocks of birds or single large ones
are seen, the Aerodrome Operator or Bird Control Unit must be informed;
(10) warnings of the presence of water on runways (as described in Chapter 7);
(11) information on the location and operational status of any arrester gear installation.
9. Grass Aerodromes
9.1 The CAA has given guidance to operators and pilots as to the percentage increase to be
added to landing/take-off distance on grass aerodromes in wet conditions. In the landing
case, a higher figure is added when the surface is ‘very wet’ as opposed to ‘damp’.
Controllers should appreciate the significance of these conditions and are to warn pilots of
arriving aircraft when ‘very wet’ surface conditions are known to exist.
10.2 Aerodrome Control responsibility on the apron is limited to providing advice and
instructions to assist the prevention of collisions between moving aircraft. The apron may
be out of sight from some visual control rooms and in these circumstances any of the
following procedures, adapted if necessary to suit local conditions, may be used to control
moving aircraft:
(1) An aircraft is cleared to taxi. A second aircraft may be given taxi clearance plus
information on the position and intention of the first aircraft, with clear instruction to
“follow” or “give way” to it;
(2) An aircraft is cleared to taxi and all further requests for aircraft movement are
refused until the first aircraft comes into sight of the controller. A second movement
is then approved following the same procedures;
(3) An aircraft is cleared to taxi and asked to report when clear of the apron or passing
an easily identifiable reference point. A second movement may then be cleared
subject to the known progress of the first.
10.3 Vehicles moving along a runway or taxiway shall give way at all times to aircraft taking-
off, landing, taxiing or being towed, except that emergency services vehicles proceeding
to the assistance of an aircraft in distress shall be afforded priority over all other surface
movement traffic. In the latter case, all movement of surface traffic should, to the extent
practicable, be halted until it is determined that the progress of the emergency vehicles
will not be impeded. The phrase “give way” must not be used in RTF phraseology to
vehicles to resolve conflictions between vehicles and aircraft on the manoeuvring area.
10A.3 When a clearance to cross a runway in use is issued a report vacated instruction shall be
included. However, this instruction may be omitted when Aerodrome Control has
continuous sight of the aircraft or vehicle crossing.
10B.2 At units where flight progress boards are not used, such runway occupancy is to be
shown effectively by a suitable method similar to the above.
10B.3 Vehicles fitted with appropriate equipment operating on an active runway, e.g. during
runway inspection or short term maintenance, are to be transferred to a RTF frequency
which will enable them to hear transmissions to and from aircraft using that runway.
10C.2 A runway incursion is any occurrence at an aerodrome involving the incorrect presence of
an aircraft, vehicle or person on the protected area of a surface designated for aircraft
take-off and landing. The protected area of a surface for aircraft take-off and landing is
determined by the existence and location of the runway strip, clear and graded area,
obstacle free zone and ILS sensitive areas. The precise configuration of these areas is
dependent on the aerodrome layout and the operations that are taking place.
10C.3 Pilots and airside vehicle drivers who are uncertain of their position on the manoeuvring
area are one of the factors contributing to runway incursions. A loss of accurate positional
awareness can occur at any point on the manoeuvring area. It is most critical when it
occurs close to, or on, the runway.
10C.4 Pilots or vehicle drivers who are lost, or uncertain of their position, on the aerodrome
manoeuvring area will stop and notify the ATS unit of the circumstances, including their
last known position. However, if the pilot or vehicle driver recognises that they are on a
runway and are able to locate a nearby suitable taxiway, they should vacate the runway
as expeditiously as possible, unless otherwise instructed by the ATS unit; and then, stop
the aircraft/vehicle. Controllers shall issue instructions to the pilot or vehicle driver in order
to eliminate or mitigate any potential hazards arising from the aircraft or vehicle being in
the wrong position.
10C.5 An ANSP may consider it valuable in safety terms to define in MATS Part 2 when aircraft
have vacated the runway.
issued and aircraft later in the departure sequence will be subjected to jet blast or
propeller slipstream from preceding departures.
Note: Research has demonstrated that the affected area behind a large aircraft with engines at
ground idle extends up to 600 metres.
(1) To monitor the movements of aircraft and vehicles on the manoeuvring area;
(2) To provide advice and assistance for the safe and efficient movement of aircraft and
vehicles on the manoeuvring area. This should include the following:
(a) To ensure that departing aircraft are lined up on the correct runway;
(b) Determining that a runway is clear of aircraft and vehicles;
(c) To ascertain that aircraft have commenced take-off run;
(d) To monitor the positions of traffic in order to facilitate switching of taxiway
lighting;
(e) To monitor and assist emergency service vehicles when required.
(2) By correlating an identified SMR position from another ATS surveillance system
source; or
(3) By correlating an SMR position complying with an ATC instruction for a specified
manoeuvre; or
10I.2 SMR normally covers all runways and taxiways on the aerodrome. In the event of
equipment failure, the controllers shall immediately advise all aircraft being assisted.
11.2 Those items which are known to have been received by the pilot may be omitted. When
requested, aircraft shall be provided with a time check; such time checks shall be accurate
to the nearest minute. However, pilots have been requested to make arrangements to
obtain time checks from other sources whenever possible.
11A.2 Heavy aircraft are not to be given clearance or instructions that would require the use of
more than normal power for taxiing or for entry on to the runway. Heavy aircraft, when at
the holding position, are not to be cleared for an immediate take-off.
11A.3 In the interests of safety, use of the active runway for taxiing purposes is to be kept to a
minimum.
11A.4 Controllers are not to instruct aircraft or vehicles to cross illuminated red stop-bars used at
runway and intermediate taxiway holding positions. The Aerodrome Operator may decide,
on the grounds of safety, that inoperable stop-bars and associated taxiways be withdrawn
from service and alternative routes used where practicable.
11A.5 Where illuminated red stop-bars are used at runway holding positions they are only to be
de-selected when clearance has been given for an aircraft or vehicle to enter the runway.
If a conditional clearance has been issued in respect of a landing aircraft the stop-bar
must not be deselected until the landing aircraft has passed the position at which the
vehicle or aircraft will enter the runway. This requirement may be satisfied either visually
by the controller or by the use of SMR/SMGCS as specified in MATS Part 2.
11A.6 For aircraft departing from the same runway holding position, when a conditional line up
clearance has been issued to a succeeding departing aircraft the illuminated red stop-bar
may remain de-selected provided that it will be the next movement on that runway.
Meteorological restrictions applicable to this procedure are to be specified in MATS Part 2.
11A.7 On the occasions when the withdrawal of inoperable stop-bars is not possible and the
stop-bars cannot be readily suppressed, under exceptional circumstances, an aircraft may
be instructed to cross such an illuminated stop-bar subject to the following minimum
conditions:
(1) The affected runway or intermediate holding position and the aircraft are visible to
the controller. This requirement may be satisfied by the use of SMR/SMGCS as
specified in MATS Part 2. When an aerodrome is not SMR/SMGCS equipped, local
alternate solutions based on risk assessment and detailed in MATS Part 2 may be
employed.
(2) The phraseology used is to leave the pilot or driver in no doubt that the crossing
instruction only applies to the particular inoperable stop bar. Conditional clearances
shall not be used under these circumstances.
(3) Additional MATS Part 2 procedures may be required where local risk assessments
have identified that further mitigation measures may be necessary.
11A.8 In all cases particular care should be taken if this contingency procedure is to be used in
Low Visibility Operations or at night as the green taxiway centreline lights linked to the
stop-bar will not be available.
12.2 Care must be exercised when clearing an aircraft to the holding point of the runway- in-
use, for the aircraft is then permitted to cross all runways which intersect the taxi route
designated in the clearance whether active or not. Therefore when a taxi clearance
contains a taxi limit beyond a runway, it is to contain an explicit clearance to cross that
runway. If such a clearance cannot be given, the clearance limit and the specified route
must exclude that runway and any route beyond it. When the controller considers it
appropriate, the phrase “hold short” may be used to emphasise that the aircraft is not
authorised to cross an intermediate runway, e.g. “taxi to holding point D2, hold short of
runway 25R”.
12.3 If an aircraft wishes to depart from an aerodrome in airspace where VFR flight is permitted
and the flight details are unknown, the pilot is to be asked “Are you departing VFR?”.
12.4 The phrase “follow the…” is useful when issuing taxi instructions. However, controllers are
warned that this phrase could lead to an aircraft inadvertently following another past a
holding position or on to the active runway. Controllers are therefore to use caution when
issuing taxi instructions containing the phrase “follow the…”; especially in the area of the
active runway or runway holding positions.
12.5 Controllers must be alert to the potential for visual misidentification of aircraft on the
aerodrome. This is particularly important when an aircraft may not be displaying a livery
synonymous with its callsign.
13.2 To guard against pilots misinterpreting a clearance message as permission to take- off,
after an aircraft has been instructed to hold at a runway holding position and a clearance
message is passed, the clearance message shall be prefixed with a repetition of the
appropriate holding instruction.
13.3 Conditional clearances shall not be used for movements affecting the active runway
except when the aircraft or vehicles concerned can be seen by both controller and pilot or
driver. Conditional clearances are to relate to one movement only and, in the case of
landing traffic, this must be the first aircraft on approach. However, when a number of
aircraft are at a holding position adjacent to a runway, then a conditional clearance may
be given to an aircraft in respect of another that is ahead in the departure sequence. In
both cases no ambiguity must exist as to the identity of the aircraft concerned.
(4) pilots are advised of the number of aircraft ahead in the departure sequence, and
the position/runway from which these aircraft will depart;
(5) the physical characteristics of the runway do not render preceding aircraft in the
departure sequence invisible to succeeding aircraft on the same runway.
14.2 When line-up will take place at a position other than for a full-length runway departure the
intermediate holding position designator shall be included in the line-up instruction.
Controllers may include holding position designators in any clearance to line-up as
considered appropriate.
14.3 Conditional line-up clearances have been identified as a significant contributory factor in
many runway incursion incidents. The use of non-standard phraseology when issuing a
conditional line-up clearance exacerbates the risk of misunderstanding or confusion,
which has the potential to increase the likelihood of runway incursions.
14.4 The phrase “(Callsign), line-up in turn” has been identified as ambiguous and misleading
and is not to be used.
15.2 Unless MATS 2 states otherwise, take-off clearance shall include the designator of the
departure runway.
15.3 Take-off clearance may be issued when the aircraft is at or approaching the holding
position for the runway in use or when the aircraft is lined up on or entering the runway in
use. Controllers may include holding position designators in any clearance to take-off as
considered appropriate.
15.4 A take-off clearance shall be issued separately from any other clearance message. If an
aircraft is lined up on the runway and a revised clearance or post departure instructions
need to be passed, the revised clearance or post departure instructions shall be prefixed
with an instruction to hold position.
15.5 An aircraft shall not be permitted to begin take-off until the preceding departing aircraft is
seen to be airborne or has reported ‘airborne’ by RTF and all preceding landing aircraft
have vacated the runway in use.
15.6 A departing aircraft shall not be given instructions which would require it to make a turn
before it has reached a height of 500 feet. This need not apply in the case of a light
aircraft.
(1) The ATC clearance from Area Control (if required) has been passed and
acknowledged; and
(2) Approach Control have authorised its departure and any specific instructions have
been passed to the aircraft, e.g:
15B. Expedition
15B.1 When given the instruction “cleared for immediate take-off” it is expected that the pilot will
act as follows:
(1) At the holding position, taxi immediately on to the runway and commence take-off
without stopping the aircraft. (Not to be given to Heavy aircraft);
(1) expedite departing aircraft by suggesting a take-off direction which is not into wind.
The pilot has the right to reject the suggestion;
(2) reduce the overall delay to traffic by altering the order in which he clears aircraft to
take-off;
(3) when ATS surveillance systems are not available, clear departing IFR flights to
climb VMC and maintain their own separation until a specified time, location or level,
if reports indicate that this is possible.
16.2 In certain circumstances the aerodrome controller may consider that it is necessary to
cancel take-off clearance after the aircraft has commenced the take-off run. In this event
the pilot shall be instructed to stop immediately and to acknowledge the instruction.
16.3 The cancellation of a take-off clearance after an aircraft has commenced its take-off roll
should only occur when the aircraft will be in serious and imminent danger should it
continue. Controllers should be aware of the potential for an aircraft to overrun the end of
the runway if the take-off is abandoned at a late stage; this is particularly so with large
aircraft or those operating close to their performance limit, such as at maximum take-off
mass, in high ambient temperatures or when the runway braking action may be adversely
affected. Because of this risk, even if a take-off clearance is cancelled, the commander of
the aircraft may consider it safer to continue the take- off than to attempt to stop the
aircraft.
16.4 As the aircraft accelerates, the risks associated with abandoning the take-off increase
significantly. For modern jet aircraft, at speeds above 80kt flight deck procedures balance
the seriousness of a failure with the increased risk associated with rejecting the takeoff.
For example, many system warnings and cautions on the flight deck may be inhibited
during the take-off roll, and between 80kt and V1 most aircraft operators define a limited
number of emergency conditions in which the take-off will be rejected. Consequently, at
speeds above 80kt, the take-off clearance should normally only be cancelled if there is a
serious risk of collision should the aircraft continue its take-off, or if substantial debris is
observed or reported on the runway in a location likely to result in damage to the aircraft.
The critical speed will be dependent on the aircraft type and configuration, environmental
conditions and a range of other factors but, as a general rule, for modern jet aircraft, it will
be in the region of 80kt airspeed. The typical distance at which a jet aircraft reaches 80kt
is approximately 300m from the point at which the take-off roll is commenced. The unit
MATS Part 2 shall contain further guidance on the likely position on the runway at which
those aircraft types commonly using the aerodrome typically reach 80kt.
16.5 Controllers should also be aware of the possibility that an aircraft that abandons its take-
off may suffer overheated brakes or another abnormal situation and should be prepared to
declare the appropriate category of emergency or to provide other suitable assistance.
Position 1: Aircraft reports on ‘downwind’ leg when abeam upwind end of the runway.
Position 2: Aircraft reports ‘late downwind’ if it is on the downwind leg, has been unable to
report ‘Downwind’ and has passed the downwind end of the runway.
Position 5: Aircraft reports ‘long final’ (between 8 and 4 miles) when aircraft is on a straight-
in approach.
Note: For light aircraft operations, circuit dimensions may be reduced, but the relative RTF
reporting points are maintained.
18A.2 Aircraft may be cleared to position overhead the aerodrome for a standard overhead join.
In these circumstances the aircraft will report overhead at 2,000 feet above aerodrome
elevation, subject to remaining in VMC; and, when cleared to descend will route to the
dead side of the circuit descending to circuit height. The aircraft will then cross the upwind
end of the runway in use at circuit height, then position accordingly into the existing traffic
pattern to report downwind. Any variance on this procedure must be notified in MATS Part
2 and the phraseology “standard overhead join” must not be used in such circumstances.
18A.3 If an aircraft enters a traffic circuit without proper authorisation, the possibility of an
emergency must be recognised. The aircraft should be permitted to land if its actions
indicate that it wishes to do so and, if necessary, other aircraft are to be instructed to give
way.
19. Landing
19.1 Unless MATS Part 2 states otherwise, landing, low approach, and touch and go
clearances shall include the designator of the landing runway.
19.2 Unless specific procedures have been approved by the CAA, a landing aircraft shall not
be permitted to cross the beginning of the runway on its final approach until a preceding
aircraft, departing from the same runway, is airborne.
19.3 When a pilot requests the instantaneous surface wind, the word “instant” is to be inserted
to indicate that the wind being reported is not the two minute average.
19.4 When aircraft are using the same runway, a landing aircraft may be permitted to touch
down before a preceding landing aircraft which has landed is clear of the runway provided
that:
(1) the runway is long enough to allow safe separation between the two aircraft and
there is no evidence to indicate that braking may be adversely affected;
(3) the preceding landing aircraft is not required to backtrack in order to vacate the
runway;
(4) the controller is satisfied that the landing aircraft will be able to see the preceding
aircraft which has landed, clearly and continuously, until it has vacated the runway;
and
(5) the pilot of the following aircraft is warned. Responsibility for ensuring adequate
separation rests with the pilot of the following aircraft.
Therefore, with the exception of instructions to go-around, instructions shall not be issued
to aircraft in the final stages of approaching to land that would require it to deviate from its
expected flight path unless exceptional and overriding safety considerations apply.
(1) aircraft information with respect to other aircraft in the same formation;
(2) aircraft operating in different areas or lanes on aerodromes equipped with runways
suitable for simultaneous landings or take-offs;
(1) determine the landing order, spacing and distance from touchdown of arriving
aircraft;
(3) enable the controller to confirm that the initial track of a departing aircraft conforms
with the clearance issued;
(4) provide information to aircraft on the position of other aircraft in the circuit or carrying
out an instrument approach.
21.2 When approved by the CAA and subject to sub-paragraph (2) below:
(a) following identification, validate SSR codes of departing aircraft and verify
associated Mode C read-outs;
(b) monitor the progress of overflying aircraft identified by Approach Radar Control
to ensure that they do not conflict with the tracks of arriving or departing aircraft;
21.3 Units where Air Control and GMC are combined may apply to the CAA to be exempt from
paragraph 21.2 (2)(b) above.
22.2 For aircraft operating on the aerodrome QNH, the low approach altitude restriction is to be
based on 400ft plus threshold elevation, rounded up to the nearest 50ft.
22.3 The runway in use shall be kept clear of aircraft and vehicles if an approaching aircraft is
likely to descend below 400 feet above the threshold elevation.
23.2 When selecting the runway-in-use, Aerodrome Control shall take into consideration other
factors such as traffic pattern, the length of runways or landing runs, approach aids
available and any meteorological conditions which may be significant to the choice of
runway. At certain aerodromes more than one runway may be in use at any one time.
23.3 There are numerous reasons for using an out of wind runway, for example - operations,
efficiency and noise abatement.
23A.2 A runway shall not be selected for noise abatement purposes for landing operations
unless visual or instrument glide path guidance is available to that runway.
23A.3 Noise abatement shall not be the determining factor in runway nomination when it is
known that the crosswind component, including gusts, exceeds 15 kt, or the tailwind
component, including gusts, exceeds 5 kt.
23A.4 Additional parameters when noise abatement is not to be used as a determining factor in
runway selection shall be agreed with the aerodrome licensee and incorporated into
MATS Part 2, taking due consideration of:
(4) If the pilot, prompted by safety concerns, considers that a runway offered, including
those for noise abatement purposes, is not suitable, he may refuse that runway and
request permission to use another. In such circumstances, controllers shall inform
pilots of the expected delay necessary to facilitate a change of runway.
(3) Contractors working on the aerodrome who will be affected by the change;
(b) the withdrawal or return to use of runways, taxiways and associated lighting
aids;
25B.2 The Aerodrome Operator may take some time to assess the situation. During this period
the controller is to decide the action to take according to the circumstances:
(1) Where an operational occurrence has resulted in an obstruction in the vicinity of the
runway-in-use:
(a) withhold take-off and landing clearance when the obstruction is within the
cleared and graded area of the runway;
(b) withhold take-off and landing clearance if there is any doubt as to the position of
the obstruction.
Pilots will be advised of the reason for withholding clearance together with the
position and nature of the obstruction.
(2) When the obstruction is obviously outside the cleared and graded area but on or in
the vicinity of the apron or manoeuvring area the pilot will be advised of the position
and nature of the obstruction. It is the responsibility of the pilot to decide whether or
not to continue operations.
25B.3 When the Aerodrome Operator has decided the operational status of the apron or
manoeuvring area they will inform ATC. The parent ACC should be informed of any
situations which may restrict operations at the aerodrome.
informs ATC of a change in the extent of the services or equipment which will be available
during this period the pilot should be advised accordingly.
(5) Signals or methods of indicating that vehicles and personnel must leave the
manoeuvring area.
28.2 The representative of the working party should possess an authorisation to work on the
aerodrome issued by the Aerodrome Operator. This is to be counter-signed by the senior
controller, subsequent to the briefing, and a copy retained or a record of the briefing
entered in the ATC Watch Log.
30.2 Following any incident, or suspected incident, on a runway involving tyre failure, aircraft
structural failure or, in the case of turbine engined aircraft, engine malfunction, the runway
is to be inspected before any other aircraft are allowed to use it.
30.3 Runway inspections are to be arranged through the Aerodrome Operator at aerodromes
where the ATC unit is not responsible for surface inspections. If special arrangements
have been made for aerodrome inspections to be carried out by the ATC unit, they should
be conducted according to the instructions in Chapter 6.
31A. Introduction
31A.1 ATC should co-operate with the Aerodrome Fire Service and Aerodrome Operator in the
pre-planning of preferential routes through the manoeuvring area. Controllers are to
ensure that they are familiar with these routes.
31C.2 ATC units shall ensure that unplanned reductions in the RFFS category are notified to
flight crew either via ATIS or directly by RT. On receipt of such information, flight crew will
decide whether to continue their flight or to divert according to their Company Standard
Operating Procedures. Controllers should normally expect the aircraft to divert if the
available RFFS category does not meet that required for the aircraft type as described in
CAP 168 Licensing of Aerodromes.
31C.3 Exceptions to the above could be expected for emergency landings, and for occasions
when, in the pilot’s opinion, a diversion or hold may introduce a more significant hazard.
Controllers shall continue to provide normal ATS and clearances in response to flight crew
intentions.
31D.2 ATC, in consultation with the Aerodrome Fire Service, is to assist in providing practice
emergencies which are to be held frequently and made as realistic as possible.
31E.2 Arrangements shall be made in co-operation with the Aerodrome Fire Officer for ATC to
provide instruction to Aerodrome Fire Service personnel concerning light and visual
signals used on an aerodrome.
31F.2 The Aerodrome Fire Service is frequently called upon for ‘Special Services’. These
include attendance at accidents to personnel, pumping out flooded premises, clearance of
fuel spillage etc. If any of these is considered to be an emergency and occur within the
radius of action of the Aerodrome Fire Service, attendance will be made immediately. ATC
will be informed and advised of any depletion of the emergency services. If the services
are depleted the Watch Supervisor at the parent ACC must be informed.
SECTION 2: CHAPTER 2
2.2 A general description of intensity settings to be used when RVR operations are in force
are contained in Section 3.
2.3 At certain aerodromes, where RVR reference lights are in use, the runway lighting may be
temporarily switched off if this will facilitate an accurate count of the reference lights for
RVR purposes. This shall not be done either:
(3) after an aircraft has reached 5 miles from touchdown on a radar approach.
3. Periods of Display
3.1 Aerodrome lighting appropriate to the runway a pilot is to use shall be displayed for an
appropriate period of time as specified in MATS Part 2, before any ETA and after any ATD
as follows:
(1) By day: High intensity systems, where installed on the runway to be used, whenever
the visibility is less than 5 km and/or the cloud base is less than 700 feet;
3.2 When the reported visibility consists of two values, the lower of the two values shall be
used when determining whether or not to illuminate aerodrome lighting.
3.3 MATS Part 2 requirements for the display of aerodrome lighting before any ETA and after
any ATD shall be based on local assessment, which shall take into account, but not be
limited to, the technical specifications of the lighting system in use, including the time
taken for the lighting to reach the required brilliancy, and the availability of lighting in the
event of a departing aircraft making an emergency return to the aerodrome.
3.4 When the ATD of an aircraft is such that lighting will be displayed after aerodrome closing
time, the pilot concerned should be warned that the aerodrome will close at the normal
published time, and advised that lighting only will be displayed after his departure. The
availability of other aerodrome services, e.g. the Aerodrome Fire Service, approach aids,
etc., during this period should also be clearly stated. Availability of aerodrome services
outside of published hours is detailed in Section 2 Chapter 1.
3.5 Obstruction lighting, hazard beacons and aerodrome light beacons shall be displayed at
night during the published hours of watch. Hazard beacons shall also be displayed by day
whenever the visibility is less than 3500 metres.
3.6 In addition to the display periods shown above, lighting may be displayed at any other
time if it is requested by the parent ACC, required by MATS Part 2 or considered
necessary by the controller.
SECTION 2: CHAPTER 3
3. Misfires
3.1 Appropriate misfire procedures shall be contained in either MATS Part 2 or the Aerodrome
Manual.
4. Storage
4.1 Signal pistols, pyrotechnics and bird scaring cartridges will be kept in accordance with
current firearms legislation.
5.2 Lasers and searchlights are grouped together under the generic term ‘Light Displays’.
Although fireworks present less of a problem than lasers and searchlights, the effect and
hazard is such that they are included in the term ‘Light Displays’. Light displays also
includes the outdoor use of lasers, searchlights and fireworks for research measurement
and non-entertainment activities.
5.3 Light displays must never be directed at, or towards, aircraft or aerodromes.
5.4 Specific guidelines apply to light displays using lasers and searchlights within 500 metres
either side of extended runway centrelines within ten miles of an aerodrome. Within three
miles of an aerodrome but not on the extended centreline, the same guidelines apply but
with the addition that any light should not stray towards the aerodrome or the extended
centreline. In both cases, information should be passed to any affected aircraft. If a pilot
requests that the lights are extinguished or if ATC consider this necessary, then action
should be taken without delay.
5.5 Guidelines have also been laid down for fireworks displays which should be limited to a
height of 1500 ft above ground level and should not take place within 500 metres either
side of the extended runway centreline within five miles of an aerodrome, or within two
miles radius of an aerodrome. However, published guidelines apply if a fireworks display
is to take place within these parameters.
5.6 For the light displays described above, CAA Airspace Regulation is responsible for the
promulgation of the event by NOTAM and co-ordinating with the relevant ANSP as
required.
5A.2 Whilst the majority of incidents appear to be the result of opportunists, the number of
reported events is increasing significantly, and reports of aircraft being subjected to
illumination from multiple co-ordinated lasers have been received.
5A.3 UK police forces treat all reports of laser attacks upon aircraft and ATS facilities very
seriously, and will respond to any reported activity. ATSUs are encouraged to establish
procedures with their local police authority to facilitate the rapid reporting of all such
incidents, and the passing of all information that may assist in the apprehension of those
responsible. Such guidance should be published in the unit MATS Part 2.
(2) Seek as much information regarding the incident as possible from the pilot,
including:
(3) Anticipate the need for the pilot to adopt manoeuvres/operational techniques to
minimise the impact on the aircraft;
(4) Dial 999, and pass all relevant information to the local police;
(5) Warn pilots of other aircraft in the vicinity that laser activity has been reported. The
duration of providing these warnings will be stated in MATS Part 2;
(6) Record the details in the ATC watch log and complete an ATC Occurrence Report
SRG 1602.
(1) Look away from the laser beam if possible. Do not attempt to find the light source by
staring at the laser;
(2) Shield eyes and consider the feasibility of lowering/raising ‘sun blinds’ to reduce the
effects of the laser;
(3) Advise aircraft under your control that a laser is illuminating you;
(4) Avoid rubbing the eyes to reduce the potential for corneal abrasion;
(5) Consider the feasibility of increasing ambient light levels to minimise any further
illumination effects;
(6) Consider handing over the control position to a colleague in a position not exposed
to the laser;
(7) Where local arrangements have not been established, inform a Supervisor who in
turn can: decide on restricting traffic in/out of the aerodrome; inform the aerodrome
operator; dial 999 and pass all relevant information to the local police;
(8) Ensure the event is recorded in the ATC watch log and reported for further
investigation by completing an ATC Occurrence Report (SRG 1602).
5C.2 Guidance to ATSU staff in making a decision on whether or not to see an eye specialist
following exposure to a laser beam is provided at Appendix I ‘Aviation Laser Exposure
Self-Assessment (ALESA)’.
SECTION 2: CHAPTER 4
Windshear
1. Introduction
1.1 Windshear is a sustained change in the wind velocity along the aircraft flight path, which
occurs significantly faster than the aircraft can accelerate or decelerate.
1.2 Windshear can occur at any level, but it is low-level windshear, occurring from the surface
to a height of approximately 1500 feet which can cause problems of sufficient magnitude
to affect the control of aircraft in departure or final approach phases of flight.
(2) The presence of low level inversions where the surface wind will be significantly
different from that at only a few hundred feet above the ground.
(3) Local terrain or buildings considered in relation to wind speed and direction; such
large obstructions can cause windshear as well as the more usual turbulence and
gusts.
3. Effects of Windshear
3.1 A combination of factors can make the analysis of windshear very complex, but three
simple examples of the hazards of low-level windshear are shown overleaf:
(1) As the aircraft flies from A to B and traverses the windshear line, the inertia of the
aircraft maintains the ground speed of 170 kt and the change of wind vector causes
a sudden fall in airspeed. This can result in reduced lift until the inertia of the aircraft
has been overcome and the original airspeed regained. Clearly this may be
hazardous at critical climb-out speeds;
B
180 Kt
22200KK
tt
40 Kt 130 Kt
117700KKtt
10 Kt
G/S 170 Kt
A
(2) If an aircraft on final approach passes through a windshear line which causes a
sudden loss of airspeed and a consequent increase in the rate of descent, a rapid
application of power will be required if the aircraft is not to sink to a dangerously low
height;
50 Kts
Increased power
20 Kts requirement
(3) If the aircraft passes through a windshear line from a tailwind to a headwind
component the inertia of the aircraft results initially in an increased airspeed and a
deviation above the glidepath. The pilot’s instinctive power reduction can result in
the aircraft being short of power with a high rate of descent as the glidepath is
approached and the effect of the inertia is lost. A rapid increase of power is now
required if the aircraft is not to sink below the glidepath at a dangerously low
altitude.
Headwind
Increased power
requirement
3.2 Due to the need to maintain both a safe margin above the stalling speed and a clearly
defined flight profile, particularly during the climb- out and approach phases of flight,
sudden changes in airspeed must be countered very rapidly. If the aircraft is in a turn
when a windshear alert is generated, the crew may level the wings to maximize the climb
gradient, unless a turn is required for obstacle clearance. Furthermore due to high flight
deck workload the reply ‘Standby’ in response to ATC instructions is not unusual during
such events.
4.2 Onboard windshear alerts take precedence over TCAS annunciations and due to the high
flight deck workload during windshear recovery manoeuvres the TCAS display may not be
monitored to the same extent as during normal operations. The priority of the crew during
windshear recovery manoeuvres is to keep the aircraft under control whilst ensuring
terrain clearance. Rates of climb during such recovery manoeuvres, which employ the use
of maximum thrust, will significantly exceed those during missed approaches executed for
reasons such as an occupied runway, or lack of visual contact in poor visibility. These
high rates of climb, especially when associated with a missed approach which has a
relatively low level-off altitude, can result in pilots exceeding their cleared level and
eroding separation from other aircraft.
5. ATC Action
5.1 In the event of a pilot executing a missed approach due to a windshear alert, controllers
should be prepared for the aircraft to exceed the missed approach altitude. Controllers
should provide enhanced traffic information as necessary and provide instructions and
advice as deemed appropriate to ensure safety.
5.2 Whenever a pilot reports windshear conditions to ATC, the information shall be relayed to
subsequent inbound and outbound aircraft until confirmation is received that the condition
no longer exists.
(2) The height or height band where the shear was encountered;
(4) Details of the effect of the windshear on the aircraft, e.g. speed gain or loss, vertical
speed tendency, change in drift.
6. ATIS Broadcasts
6.1 At aerodromes where ATIS is available windshear information may be included in the
broadcasts. Controllers should amplify the information for individual aircraft if necessary.
SECTION 2: CHAPTER 5
Prevailing Visibility
1. Introduction
1.1 Prevailing visibility is defined as the visibility value that is reached or exceeded within at
least half the horizon circle or within at least half of the surface of the aerodrome. These
areas could comprise contiguous or non-contiguous sectors.
2.2 When the visibility is fluctuating rapidly and the prevailing visibility cannot be determined,
only the lowest visibility will be reported, with no indication of direction.
METAR EGxx 1250 1800 0800NE … should be transmitted as “Weather at one two five
zero, visibility one thousand eight hundred metres, eight hundred metres to the North East
….”
3.2 Certain ATC procedures are implemented during specific visibility conditions. When two
visibility values are present in a report, the lower of the two values shall be used to
determine whether to implement such procedures.
SECTION 2: CHAPTER 6
Aerodrome Inspections
1. Introduction
1.1 The Aerodrome Operator is responsible for all aerodrome inspections. However, special
arrangements may be made at some aerodromes for these duties to be delegated to the
ATC unit.
1.2 Aerodrome surface and lighting inspections are carried out to ensure that:
(1) ATC becomes aware of any unserviceabilities or obstructions that may affect the
use of the aerodrome and are able to supply pilots with accurate Essential
Aerodrome Information;
(5) during snow and ice conditions as frequently as weather conditions warrant;
(6) when considered necessary by ATC, the Aerodrome Operator or as detailed in local
instructions.
2.3 At aerodromes with runways, the inspection should cover the runway-in-use and those
likely to be used prior to the next regular inspection, together with their associated
prepared strips, clearways, stopways and appropriate taxiways.
2.4 At all grass aerodromes, the inspection should cover the areas likely to be used prior to
the next regular inspection, together with any permanent or delineated taxiways. Where a
grass area exists for landing light aircraft this area should be included in the inspection.
2.5 The person carrying out the inspection is not normally required to proceed outside the
aerodrome boundary. He should carry out his inspection from a vehicle driven slowly over
the area to be inspected, halting as necessary when individual items require closer
inspection. He should report his findings in accordance with MATS Part 2.
2.6 In the following paragraphs ‘temporary obstructions’ means anything that would impede
the normal movement of aircraft or infringe current aerodrome obstruction criteria.
(1) the runways, stopways, clearways, taxiways and holding areas are free from
obstructions, collections of loose stones, etc;
(2) temporary obstructions that exist on, or adjacent to, the runways or taxiways are
properly marked or lighted;
(4) runway indicator boards, traffic signs, boundary markers, etc., are serviceable and in
position.
2A.2 A note should be taken of the exact position of any obstruction or unserviceability
observed. Any of the above conditions that are encountered should be reported to the
section whose responsibility it is to deal with them.
(2) runways and taxiways are delineated if covered with snow or ice and a note taken of
the extent of sweeping and sanding carried out.
3.2 The measurement and reporting of snow, slush and ice conditions on runway surfaces is
described in Chapter 8.
3.3 The responsibility for clearing, sanding and marking will remain with the Aerodrome
Operator who should maintain close liaison with ATC.
5. Reporting Action
5.1 Unserviceabilities or obstructions during aerodrome surface or lighting inspections should
be recorded on the appropriate form or log and the information disseminated in
accordance with MATS Part 2.
5.2 Where urgent attention is necessary, e.g. for marking, lighting or immediate repair, details
should be passed to the responsible section by telephone in accordance with local
arrangements.
SECTION 2: CHAPTER 7
Wet Runways
1. Introduction
1.1 It is recognised that a need exists to warn pilots of the presence of water on a runway.
1.2 The Aerodrome Operator is responsible for assessing runway surface conditions.
1.3 When the presence of water on a runway is brought to the attention of the controller, the
information shall be passed to aircraft.
Table 1:
DRY Note: Reports that the runway is dry are not normally to be passed to pilots.
If no runway surface report is passed, pilots will assume the surface to be
dry.
The surface shows a change of colour due to moisture.
DAMP
Note: If there is sufficient moisture to produce a surface film or the surface
appears reflective, the runway will be reported as WET.
The surface is soaked but no significant patches of standing water are
visible.
WET
Note: Standing water is considered to exist when water on the runway
surface is deeper than 3mm. Patches of standing water covering more than
25% of the assessed area will be reported as WATER PATCHES.
Significant patches of standing water are visible.
WATER PATCHES
Note: Water patches will be reported when more than 25% of the assessed
area is covered by water more than 3mm deep.
Extensive patches of standing water are visible.
FLOODED
Note: Flooded will be reported when more than 50% of the assessed area is
covered by water more than 3mm deep.
2.2 When reported, the presence or otherwise of surface water on a runway will be assessed
over the most significant portion of the runway, i.e. the area most likely to be used by
aircraft taking-off and landing. This area may differ slightly from one runway to another but
will approximate to the central two-thirds of the width of the runway extending
longitudinally from a point 100 m before the aiming point to 100 m beyond the aiming point
for the reciprocal runway. The assessed area may be different on runways with a
displaced threshold or other unusual configuration, e.g. starter extension. The Aerodrome
Operator is responsible for determining the exact dimensions and location of the area that
is assessed.
2.3 Reports of the runway to be used include, sequentially, the conditions in each third of the
assessed area. For example, “Runway surface is wet, water patches, wet” or “Runway
surface is wet, wet, wet”.
2.4 A brief description of any water patches greater than 9 mm in depth, which may affect
engine performance, will be appended to a runway surface condition report. In such
conditions, further information on the location, extent and depth of the water patches will
be available from the Aerodrome Operator.
2.5 A brief description of any notable quantity of water outside the assessed area, e.g. water
collected at the runway edge, will be appended to a runway surface condition report.
3. Unofficial Observations
3.1 Pilots of aircraft may report, or observations from the aerodrome control tower may
indicate, that the amount of water present or runway surface condition is different from
that being reported. Under no circumstances are controllers to pass to pilots information
that suggests that the runway surface condition is better than the official report. However,
when a pilot’s report or an observation from the aerodrome control tower indicates a
worse runway surface condition this information is to be passed and identified as such.
4. Calibrated Runways
4.1 Wet-surface friction characteristics of the runways at certain aerodromes have been
calibrated to ensure that they are of an acceptable quality. If the quality deteriorates below
an acceptable level the particular runway will be notified as liable to be slippery when wet.
4.2 When a runway, other than one notified as liable to be slippery when wet, is reported as
damp or wet, pilots may assume that an acceptable level of wheel braking is available.
When a runway is reported as having water patches or being flooded, it can be expected
that pilots will make the necessary operational adjustments as wheel braking and control
may be affected by aquaplaning.
SECTION 2: CHAPTER 8
1. Introduction
1.1 The measurement of snow, slush, ice and associated standing water is the responsibility
of the Aerodrome Operator. The ATC unit is responsible for issuing reports to pilots of
aircraft directly under their control, but the general dissemination of information is the
responsibility of the Aerodrome Operator. However, special arrangements may be made
at some aerodromes for the measurement and reporting of snow and slush to be
delegated to the ATC unit.
1.2 There is a full description of the UK Snow Plan in the UK AIP (AD) section. Annual
variations are published in an AIC before the onset of winter.
(1) Ice – water in its solid state, it takes many forms including sheet ice, hoar frost and
rime;
(2) Dry snow – a condition where snow can be blown if loose or, if compacted by hand,
will fall apart again upon release;
(3) Compacted snow – snow which has been compressed into a solid mass, that resists
further compression and will hold together or break-up into chunks if picked up;
(4) Wet snow – a composition which, if compacted by hand, will stick together and tend
to, or does, form a snowball;
(5) Slush – a water saturated snow which, with a heel and toe slap down action with the
foot against the ground, will be displaced with a splatter;
3. Significant Changes
3.1 The following changes, relating only to runway conditions, are classed as significant:
(1) Any change in surface deposit, i.e. snow turned to slush, water to ice, etc., and the
effect on braking action where appropriate;
(2) Changes in depth greater than the following: 20 mm for dry snow, 10 mm for wet
snow, 3 mm for slush;
(3) Any change in the available length or width of runway(s) of 10 per cent or more;
(4) Any change in the type of deposit or extent of coverage which requires
reclassification in item F of the SNOWTAM;
(5) Any change in the distance apart of snowbanks from the criteria declared to be the
value from which reporting begins;
(6) Any change in the serviceability of runway lighting caused by obscuring of the lights,
with particular reference to the threshold;
4.2 Feedback from aircraft operators has shown that data relating to type, depth and extent of
contamination reported for each third of the runway is useful to aircrew for performance
calculations. Each runway in use should be divided into a Touchdown Zone, a Mid Point,
and a Stop end for reporting purposes. Within each of the three zones the % coverage,
the type of contaminant, and the depth of contaminant together with the cleared runway
width and length, should be recorded and promulgated. The Aerodrome Operator or its
delegated Air Traffic Service Unit should promulgate runway surface condition using the
following format.
Table 1:
yy
4.3 Further details of the National Snow Plan and procedures for dealing with winter
contamination of aerodrome surfaces can be found in CAP 168 Licensing of Aerodromes
Appendix 3D.
SECTION 3: CHAPTER 1
Approach Control
1. Provision of Services
1.1 Approach Control Services within the UK FIRs comprise surveillance and non-
surveillance based ATS. The type of ATS to be provided depends on the classification of
airspace within which the aircraft is flying as tabulated below:
Table 1:
(1) arriving aircraft are released by Area Control until control is transferred to
Aerodrome Control;
(2) aircraft approaching from outside controlled airspace place themselves under the
control of Approach Control until control is transferred to Aerodrome Control;
(3) departing aircraft are taken over from Aerodrome Control until:
1A.2 Approach Control shall provide standard separation between Special VFR and IFR flights
and between Special VFR flights unless the CAA has approved a reduced separation.
1A.3 Participating VFR flights in Class E airspace shall be provided with a type of UK FIS
(either Traffic Service or Basic Service), subject to controller workload, in accordance with
Section 1, Chapter 12 UK Flight Information Services.
(1) arriving aircraft place themselves under the control of Approach Control until control
is transferred to Aerodrome Control;
(2) departing aircraft are taken over from Aerodrome Control until they no longer wish to
receive a service or are 10 minutes flying time away from the aerodrome, whichever
is the sooner;
(3) overflying aircraft place themselves under the control of Approach Control until they
are clear of the approach pattern and either no longer wish to receive a service or
are 10 minutes flying time away from the aerodrome, whichever is the sooner.
1B.2 Aircraft within an ATZ are required to comply with instructions from the ATC unit. Although
IFR/VFR flight within Class F/G airspace outside the ATZ is permitted without an ATC
clearance, controllers will act on the basis that pilots will comply fully with their instructions
in order to promote a safer operating environment for all airspace users.
2. Information to Aircraft
2A.2 Controllers at aerodromes located in Class C, D and E airspace are to pass traffic
information as shown in the table below.
Table 2:
Aerodrome Located in
Traffic Information to be Passed
Airspace
Class C to VFR flights on other VFR flights*;
a) to IFR flights on VFR flights*;
b) to VFR flights on IFR flights;
Note 2: In Class D airspace traffic avoidance advice must be given if requested by pilots of:
(a) IFR flights against VFR flights,
(b) VFR flights against all other flights.
Note 3: Mixed VFR and Special VFR operations can occur within Class D Airspace as a result of
the different VMC criteria for different aircraft categories and the limitations of a pilot’s
licence.
Note 4: When providing traffic avoiding advice, controllers shall remind pilots of their responsibility
to remain clear of cloud with the surface in sight.
Note 5: When the controller considers that more immediate action is required by the pilot, traffic
avoidance advice may be passed by ATC before traffic information.
(1) Pertinent data on all relevant flights including the type of flight, i.e. IFR or VFR, level
of arriving aircraft and ETA;
(3) The anticipated delay to departing IFR flights together with the reason for the delay.
(1) Lowest level at the holding facility available for use by Area Control;
(3) Revision of expected approach times issued by Area Control when Approach
Control calculations show a variation of 5 minutes or more;
(4) Arrival times over the holding point if these vary from the estimate by 3 minutes or
more;
(5) Missed approaches when re-routeing is entailed, in order that the subsequent action
may be co-ordinated;
3C.2 Any of these items can be deleted from routine practice by agreement with Area Control.
4. Co-ordination
(2) Arriving aircraft which make their first call on the tower frequency (unless they are
transferred to Approach Control).
5. Transfer of Control
(1) When an aircraft carrying out an instrument approach has become ‘number 1 to
land’, and for following aircraft when they are established on final approach and
have been provided with the appropriate separation from preceding aircraft;
(3) Aircraft approaching visually below all cloud when the reported aerodrome visibility
is 10 km or more. When the reported visibility consists of two values, the lower of
the two values shall be used when determining whether an aircraft may be
transferred to Aerodrome Control.
5A.3 In the case of 2 and 3 the volume of traffic and Aerodrome Control workload must be such
as to allow the use of one of the reduced separations permitted in the vicinity of
aerodromes. In order to clear other aircraft to descend through the cloud formation it will
be necessary for the aircraft approaching underneath to be kept more than 1000 feet
below all cloud, or for horizontal separation to be provided.
6. Delegation
(1) Callsign, type, level, route, ETA (or position) and frequency;
6A.2 Approach Control may delegate the responsibility for co-ordination to Approach Radar
Control.
vicinity of the aerodrome, providing the aerodrome controller holds an Approach Control
rating valid for that aerodrome. Details of the extent of the permitted delegation will be
published in MATS Part 2.
7. Transfer of Communication
8. VFR Flights
8.1 Approach Control shall retain all arriving VFR flights under its control until appropriate
traffic information on IFR flights and other VFR flights has been issued and co-ordination
effected with Aerodrome Control.
8.2 A particular watch should be kept for situations where a VFR flight may approach the
aerodrome in a sector in which other aircraft are letting down on an instrument approach
aid, or where sequencing is in operation. D/F indications, where available, will assist in
this respect. In these circumstances the pilot of the VFR flight should not be given
clearance for a straight-in approach and should be advised to avoid the initial and final
approach areas.
8.3 Approach Control must ensure that VFR flights are transferred in sufficient time for
Aerodrome Control to pass additional information in respect of local traffic.
8.4 Visual Reference Points (VRPs) are established to assist ATC in routeing VFR traffic and
to integrate VFR flights with IFR flights. Where VRPs are established outside controlled
airspace, controllers should not instruct aircraft to hold over such VRPs. This does not
apply to VRPs established within controlled airspace where a known traffic environment
exists. Controllers should not direct VFR traffic over VRPs unless the IFR traffic situation
specifically demands this.
8.5 When the reported meteorological conditions at aerodromes in Class D airspace reduce
below a ground visibility of 5 km and/or a cloud ceiling 1500 ft, both by day or night, ATC
shall advise pilots of aircraft intending to operate under VFR to or from such aerodromes,
and request the pilot to specify the type of clearance required.
8.6 Except for helicopters using Police; Helimed; Rescue; Electricity; Grid; Powerline, or
Pipeline callsigns, or an SAR training flight operating in accordance with MATS Part 2,
controllers shall not issue any further VFR clearances to aircraft wishing to operate in
accordance with VFR to or from an aerodrome, or enter the aerodrome traffic zone, or
aerodrome traffic circuit, of an aerodrome within Class D airspace when the official
meteorological report at that aerodrome indicates, by day or night, a ground visibility less
than 5 km and/or a cloud ceiling less than 1500 ft (SERA.5005(b)(1)&(2)).
Note 1: UK General Permission ORS4 no. 1125 permits VFR flight within a control zone at night.
Note 2: UK General Exemption ORS4 no. 1195 enables the pilot in command of an aircraft to
transit Class D airspace in accordance with VFR by day, remaining clear of cloud with
surface in sight and an indicated airspeed of 140 kt or less, with a flight visibility of 5 km or
for helicopters, a flight visibility of 1500 m. Except for commanders of a Powerline,
Pipeline, Police, Helimed, or SAR helicopters, which operate in accordance with their
respective ORS4, this exemption does not enable the pilot in command of an aircraft to
transit an aerodrome traffic zone or aerodrome traffic circuit within a control zone, when
the official meteorological report at that aerodrome indicates the values specified in
paragraph 8.6.
Note 3: UK General Exemption ORS4 no. 1222 exempts operations of helicopters conducting
Powerline; Pipeline; Police’ Helimed; Search and Rescue (SAR) flights, including SAR
training flights operating in accordance with a Letter of Agreement with the Air Traffic
Service Provider, form complying with SERA.5005(b) and SERA.5010(a) and (b).
Note 4: For the purpose of observing the meteorological conditions at an uncontrolled and/or
unlicensed aerodrome or operating site located within a control zone, and assessing
whether those conditions satisfy the minima specified in SERA.5005(b) and
SERA.5010(c) as appropriate, the Civil Aviation Authority deems the following individuals
to be competent to act as ‘accredited observers’ as required within Regulation (EU)
923/2012 Article 2(82) for their flight:
(a) The holders of valid EASA Flight Crew Licences, valid National Flight Crew Licences
and Certificates issued by, or on behalf of, the United Kingdom Civil Aviation
Authority, and third country licences deemed valid in accordance with Article 150 of
the Air Navigation Order 2016; and
(b) A student pilot-in-command (SPIC) who has passed the theoretical knowledge
examination in meteorology toward the grant of an EASA Flight Crew Licence or
National Flight Crew Licence or Certificate issued by, or on behalf of, the United
Kingdom Civil Aviation Authority within the preceding two years.
8.7 When the ground visibility consists of two values, the lower of the two values shall be
used when determining whether to implement the above procedures.
8.8 Procedures for operations into subsidiary aerodromes will be found in MATS Part 2.
9. Arriving Aircraft
9A.2 This instruction does not apply where altitudes to be assigned on particular routes have
been specifically approved by the CAA.
9B.2 Inbound estimates shall be passed at least 15 minutes prior to the arrival of the aircraft at
the designated approach fix.
9B.3 Release messages shall be passed to Approach Control in a timely manner as specified
in MATS Part 2 and shall contain the following:
(4) Estimated time and level at the holding facility, or arrival time and level at the
holding facility if the release is given after arrival;
9B.4 Area Control shall clear arriving aircraft to the holding facility if the flight is remaining
within airspace Classes A to F, give instructions to hold if necessary and include an EAT
in the clearance.
9B.5 Approach Control may issue any instructions to an aircraft released to it by Area Control.
However, that aircraft must not be instructed to climb above, or stop its descent to, the
level at the holding point agreed with Area Control and passed in the release message,
without prior co- ordination with Area Control.
9B.6 Unless approved by the CAA, Area Control shall not release arriving aircraft to Approach
Control at FL195 or above. When such procedures are approved by the CAA, MATS Part
2 shall include details of the area in which aircraft may be released and the full details of
the conditions under which the procedures may be used.
9B.7 After co-ordination with Approach Control, Area Control may clear an arriving aircraft to an
aerodrome facility, or to a visual holding point, instead of the normal holding facility.
(2) flight crew composition, competence, experience, and flight techniques used;
(4) availability and performance of visual and non visual ground aids
(5) obstacles in the approach, missed approach, and climb out areas;
9D.3 Controllers are not responsible for determining, passing or enforcing a pilot’s Aerodrome
Operating Minima. However, in accordance with Section 6 Chapter 3, controllers should
report any occurrence which they consider has endangered, or if not corrected would
have endangered an aircraft, its occupants, or any other person.
(a) Surface wind direction (in degrees magnetic) and speed. The maximum wind
speed should be included if it is 10 knots or more greater than the mean speed
and the extremes in direction when the variation is 60 degrees or more and the
mean speed exceeds 3 knots. Controllers should note that anemometers
indicate magnetic direction but meteorological reports give wind direction in
degrees true;
(b) Visibility;
(f) Relevant information reported by pilots of other aircraft, e.g. vertical wind shear,
severe icing, severe turbulence;
This information may be reduced to items (a), (e) and (f) when aircraft are below
cloud flying in VMC and able to continue VMC to the landing;
(3) Current runway surface conditions when appropriate;
(4) Any changes in the operational status of visual and non-visual aids essential for
approach and landing;
9E.2 Aircraft which have received the information above must be kept informed of the following
until they have landed:
(3) Further changes in the operational status of approach and landing aids;
9F.2 If controllers are in any doubt about the location of the ‘Centrefix’ or other position referred
to by a pilot, they are to ask the pilot to define this position and take this definition into
consideration when carrying out their controlling duties.
10.2 As a general rule, controllers shall only transmit meteorological information that has been
supplied, or agreed, by the Meteorological Office. The exceptions are:
(1) Indicated wind direction (degrees magnetic) and speed when anemometer
indicators are fitted in the control room;
(4) Information from an aircraft in flight may be passed to other aircraft when a
controller considers that it may be useful to them. Whenever this is done the
controller shall state that the information originated from an aircraft in flight and the
time at which the observation was made. Aircraft reports of meteorological
conditions that affect safety, e.g. severe icing or severe turbulence, shall always be
passed to other aircraft likely to be affected. Information on severe icing and/or
severe turbulence is to be communicated as soon as possible to the duty
meteorological forecaster who will decide whether the conditions warrant the issue
of a special report;
(5) Cloud echoes observed on the situation display. The use of ATS surveillance
systems for reporting and avoiding weather is described in Section 1, Chapter 6;
10.3 Observations of visibility and RVR passed to aircraft making an approach to land when
the visibility is less than 1500 m shall be recorded. Records shall be made available to the
CAA on request.
10.4 SIGMET messages should be relayed with the least possible delay to all aircraft likely to
be affected, but without prejudice to the control of aircraft in flight.
11. ATIS
11.1 The ATIS message is intended to provide a pilot with a range of information to enable him
to make a definite decision about his approach and landing or take-off. The ATIS
message is transmitted on a published VHF broadcast frequency or selected VORs
therefore reducing RTF loading. The message should, whenever practicable, not exceed
30 seconds.
11.2 If a departure ATIS is installed it may only be used by aircraft on the ground as the
frequency has limited range protection. Combined arrival/ departure ATIS facilities have a
greater frequency protection and so may be used both on the ground and in the air.
11.3 Each message is to be consecutively coded using the phonetic alphabet. A new message
is to be broadcast whenever there is a significant change in any of the items comprising
the message and controllers must pass such changes to pilots on the RTF until the new
ATIS message is being transmitted and has been acknowledged. All altimeter settings
transmitted in the broadcast must be individually identified.
11.4 When rapidly changing weather conditions make it impracticable to include weather
reports in the broadcast the ATIS message is to indicate that the information will be
passed on the RTF.
11.5 In the case of a departure ATIS, controllers must obtain a read-back of all relevant
altimeter settings contained in the broadcast, unless the setting will also be passed in
association with start-up or taxi clearance.
11.6 Except where the broadcast includes a specific request to do so, pilots of departing
aircraft need not acknowledge receipt of an ATIS message.
11.7 Pilots of arriving aircraft are required to acknowledge receipt of the ATIS message on
initial contact with Approach Control using the code letter allocated to the message. If a
non-current code letter is used, or if receipt of ATIS is not acknowledged, Approach
Control must pass the complete Information to Aircraft detailed in paragraph 9E.1.
11.8 Comprehensive requirements for ATIS, including message elements, can be found in
CAP 670 ATS Safety Requirements.
(1) the reported cloud ceiling is at or above the level of the beginning of the initial
approach segment; or
(2) the pilot reports at any time after commencing the approach procedure that the
visibility will permit a visual approach and landing, and a reasonable assurance
exists that this can be accomplished.
12.2 Controllers should not clear an aircraft for a visual approach when the RVR is less than
800 m. If a pilot requests a visual approach when the RVR is less than 800 m, controllers
should inform the pilot that this type of approach is unavailable and request the pilot’s
intentions.
Note: Where IRVR systems are employed, the touchdown value is used to trigger the above
procedure. Transmissometer unserviceability and the impact on ATC procedures are
detailed at Section 3 Chapter 3.
12.3 Within controlled airspace, standard separation shall be effected between such aircraft
and other IFR and/or Special VFR aircraft.
12.4 Outside controlled airspace, IFR flights in receipt of any of the UK FIS may be authorised
to conduct a visual approach. Responsibility for the provision of deconfliction advice and
traffic information continues to be dictated solely by the service being provided. Continued
ATS provision is subject to the following:
(1) Procedural Service. There is no requirement for controllers to change the level of
service provided;
(2) Deconfliction Service. When flights carrying out visual approaches descend below
the unit’s terrain safe level, controllers shall not provide Deconfliction Service, and
should instead provide a Traffic Service;
(4) Basic Service. There is no requirement to change the level of service required.
12.5 Where IFR flights are authorised to make a visual approach, pilots are to be informed of
any recommended wake turbulence separation minima.
12.6 Controllers shall exercise caution in initiating a visual approach when there is reason to
believe that the flight crew concerned is not familiar with the aerodrome and its
surrounding terrain.
(a) “This is the approach procedure for (aid) for category A aircraft. Final approach
track (degrees)”;
(b) Arrival level (if necessary);
(c) Type of reversal manoeuvre including outbound track, length in time or
distance, level instructions and direction of procedure turn where applicable.
(2) When aircraft commences final reversal: intermediate and final approach track,
intermediate and final approach fixes together with level instructions, stepdown fixes
and OCH;
(3) Missed approach point and missed approach procedure (when required).
13.2 Items (1)(b) and (1)(c) may be omitted for straight-in approaches.
13.3 If the pilot is copying down the information the whole procedure can be passed in one
message.
13.4 Even if visual reference to the ground is established before completion of the approach
procedure, the pilot will normally complete the whole procedure. At his request however,
he may be cleared to break-off the instrument procedure and carry out a visual approach.
Separation from other traffic is to be provided unless the pilot cancels his IFR plan.
14.2 Levels at holding facilities shall be assigned so as to permit aircraft to approach in their
correct order. Normally the first aircraft to arrive over a holding facility should be at the
lowest level with following aircraft at successively higher levels.
14.3 Departure times of aircraft from the holding facility shall be based on the desired time
interval between aircraft landing. If the weather conditions are such that the pilot may
encounter difficulty in completing the landing, the time interval may be increased to allow
the first aircraft to land before the second aircraft commences descent of final approach.
14.4 If a pilot advises that he is unable to comply with Approach Control holding or
communication procedures, alternative procedures requested by him should be approved
if traffic conditions permit.
15.2 When airborne holding is needed and the delay is expected to be less than that requiring
the issue of EATs, controllers shall explicitly instruct pilots to hold (at the required exact
reporting point) and provide the pilot with an estimate of the delay.
15.3 When EATs are required, they shall be passed sufficiently in advance to permit pilots to
arrange their flight paths accordingly.
15.4 The first aircraft will descend from the lowest level of the holding stack and commence
approach when instructed.
15.5 The second aircraft in the approach sequence may be instructed to descend to the level
previously occupied by the first aircraft, after the first aircraft has reported vacating it. If,
however, severe turbulence is known to exist, the instruction shall be withheld until the
first aircraft has reported at least 1000 feet below the vacated level.
15.6 The second aircraft may be instructed to leave the holding facility and descend for
approach when the required separation has been established between it and the
preceding aircraft and reasonable assurance exists that a normal landing can be
accomplished.
16.2 Unless otherwise instructed controllers shall pass EATs to aircraft with whom they are in
contact. EATs shall not normally be issued when the delay is expected to be less than 20
minutes. The statement “no delay expected” is only to be used if it genuinely reflects the
situation. However, at the request of a pilot, controllers are to give a general indication of
the likely delay based on the information available at that time.
17.2 The first aircraft to enter the holding pattern is to be advised, “no traffic delay expected”.
No instruction to leave the holding facility shall be given until the pilot indicates his
intention to attempt a landing.
17.3 Subsequent aircraft entering the holding pattern shall be advised “delay not determined
(number) aircraft holding for weather improvement”. Controllers should establish the
intention of any pilot if it has not already been stated.
17.4 When a pilot wishes to make an approach he is to be given routeing instructions to enable
him to descend clear of other traffic and return to the holding facility above other aircraft
17.5 If aircraft are making approaches in poor weather conditions the possibility of missed
approaches shall be considered. The lowest holding level at a convenient holding facility
shall normally be kept vacant for such eventualities.
18. Diversions
18.1 Where marginal weather conditions exist or where the need for diversions is likely to arise
due to the state of the aerodrome, traffic density, or for any other reason, controllers at
aerodromes are to maintain the closest liaison with operating companies and the
supervisor at the parent ACC. They shall pass, as often as necessary, the latest pertinent
information so that diversions may be anticipated and not interrupt the smooth flow of air
traffic.
18.2 When the need does arise, the controller concerned is to take the following action:
(2) Contact the ACC Watch Supervisor by telephone and advise him of the aerodrome
selected for diversion, or if none selected, seek his advice as to the one most
suitable;
(3) Obtain clearance instructions together with any other instructions to be passed to
aircraft;
(6) Advise the operating company or nominated addressee in accordance with the
instructions in Section 1.
19.2 After a diverted aircraft has landed an arrival signal shall be sent to:
19.3 At aerodromes not open on a 24-hour basis, close liaison shall be maintained with the
Aerodrome Operator and the parent ACC before watch is closed, if it is known that
diversions are likely to be received. Details of the procedures for arranging extensions of
watch will be agreed with the Aerodrome Operator and published in MATS Part 2.
(4) Time, point, and/or rate at which changes of level are made.
20.2 A clearance expiry time determined by Approach Control, when considering its own traffic,
must not be later than that issued by Area Control.
20.3 Outbound clearances issued by Area Control to Approach Control may not take into
account the need for separation from any inbound aircraft that have passed the release
point. This responsibility rests with Approach Control.
20.4 Outbound clearances issued before inbound aircraft pass the release point shall take into
account the need for separation of traffic except in cases where separation is
automatically ensured by the use of fixed operating procedures, e.g. SIDs, standing
agreements, or the outbound clearance is qualified by a “Release subject your discretion”
(RSYD) restriction.
20.5 An RSYD restriction is intended to facilitate the overall expedition of traffic where
Approach Control procedures may offer a more expeditious resolution of the confliction
than Area Control procedures. In accepting an RSYD clearance the approach controller
accepts the responsibility for the provision of separation between the outbound aircraft
and the conflicting inbound or overflying aircraft. Before clearing the outbound aircraft for
departure the approach controller must ensure that:
(1) he has received the release message on the inbound aircraft or full details of the
overflying aircraft;
(3) Before the outbound aircraft is transferred to Area Control the conflictions must have
been resolved or co-ordination effected.
20.6 Pilots of all aircraft flying instrument departures are required, on first contact, to inform the
approach/approach radar controller of their callsign, SID designator (if appropriate),
current or passing level and their cleared level. If the SID involves a stepped climb profile
then the initial altitude/flight level to which the aircraft is climbing will be given. If the pilot
does not provide the cleared level then controllers shall, without delay, either confirm that
the crew are climbing to the correct initial level or clear the aircraft to climb to a higher
altitude or flight level.
SECTION 3: CHAPTER 2
Approach Radar
1. Area of Responsibility
1.1 The area within which Approach Radar Services are provided by an Approach Radar
Control unit is determined by a number of factors, including the coverage of ATS
surveillance systems and requires approval by the CAA.
2. Services
2.1 The service provided depends on the type of airspace within which the aircraft is operating
as described below:
2.2 The extent of the ATS surveillance service which an Approach Radar Control unit may
provide will depend on the type of ATS surveillance system and the operational
procedures that have been approved by the CAA. These are described in MATS Part 2
and may include:
(3) Flightpath monitoring of approaches utilising a pilot interpreted final approach aid;
(5) ATS surveillance services to transit aircraft, through an area for which Approach
Radar Control is responsible.
2.3 Certain ATS surveillance systems are not suitable for providing separation to other aircraft
when radar approaches are being given.
3. Co-ordination
3.1 Approach radar controllers may be required to co-ordinate flights directly with Aerodrome
Control and Area Control units.
5.2 Whilst the aircraft remains under the jurisdiction of the approach radar controller any
revised or additional information must be passed to the pilot.
6. Altimeter Setting
6.1 Aircraft are to be given the QNH before commencing final approach. Aerodrome and
threshold elevations shall be available on request.
6.2 At the pilot’s request or if local procedures require, the QFE may be given.
7.2 Pilots using altitude will carry out their own conversion to obtain an obstacle clearance
altitude.
8. Position Information
8.1 The position of an aircraft is to be passed to the pilot at least once on each leg of the
circuit.
8.2 Position information for an aircraft making a straight-in approach is to be passed at least
once before it commences the final descent.
Note: Range marks on extended runway centrelines usually indicate distance from touchdown
but range rings almost always indicate distance from the position of the radar aerial head.
(3) the procedure to be followed in the event of a radio communications failure if this is
not published.
(1) the angle of the nominal descent path or the recommended descent gradient;
This may be achieved by using the published standard phraseology for SRA.
9B.2 SMAC are published in the UK AIP. They indicate the minimum altitudes available to the
controller when vectoring arriving aircraft. Controllers shall not use altitudes below those
notified on SMAC except when levels are allocated in accordance with specific
procedures that are approved for use within the final approach area.
9B.3 In exceptional cases, for example when the terrain profile is likely to generate GPWS
nuisance warnings, minimum altitudes higher than the terrain clearance minimum may be
specified for use in certain circumstances in order to minimise the likelihood of nuisance
warnings. In such cases further details shall be included in MATS Part 2.
9C.2 If it is necessary to vector an aircraft through the final approach track before subsequently
joining the approach from the opposite side, the controller shall advise the pilot prior to the
aircraft passing through the final approach track.
9C.3 Except when Continuous Descent Approach (CDA) procedures are in operation or in an
emergency, aircraft shall be positioned so as to maintain a period of stabilised level flight
before commencing descent on the glide path, on descent profile of a pilot interpreted
approach, or on the nominal descent path of a SRA.
9C.4 At units where CDA procedures are used, details of the operational procedures and the
periods of use shall be included in MATS Part 2. When CDA procedures are in use,
aircraft shall be kept at as high an altitude as is appropriate to the procedures whenever
possible and controllers shall issue descent instructions at a position compatible with the
CDA profile. This is to enable pilots to intercept the glide path or final approach descent
path without a level flight segment after descent when the CDA has commenced. Distance
from touchdown information shall be provided when issuing descent clearance and at any
other times specified by the procedure or described in MATS Part 2.
9C.5 Whenever practicable, aircraft shall be vectored to intercept the final approach track at a
distance and level such that the aircraft will cross the notified Final Approach Fix/ Point.
Closing headings are typically 40 degrees offset from the final approach track although
individual units may use other offset closing headings as detailed in the MATS Part 2. The
controller shall continue to give heading instructions until the aircraft is established on the
localiser. Controllers may instruct the pilot to report established on the localiser where it is
judged that it will aid situational awareness. Controllers shall not instruct pilots to establish
on the localiser at ranges outside the localiser Designated Operational Coverage (DOC).
If necessary, controllers shall provide additional heading instructions until the aircraft is
within the DOC.
9D.2 The controller shall use one of the following techniques when issuing a clearance to the
pilot to descend on the ILS/MLS glidepath:
(1) Clear the pilot for the ILS/MLS approach only if a descent instruction has been
issued to the level published in the ILS/MLS instrument approach procedure at the
final approach fix, or to a lower level permitted by the aerodrome’s SMAC; or
(2) Issue a conditional clearance to the pilot to descend on the ILS/MLS glidepath once
established on the localiser; or
(3) When it is necessary to ensure that an aircraft joining the ILS/MLS does not
commence descent until specifically cleared, solely instruct the pilot to report
established on the localiser and to maintain the previously assigned level.
Subsequently, the pilot shall either be cleared to descend on the glidepath or given
appropriate alternative level instructions.
Note: The use of “maintain” in sub-paragraph (3) above, is to ensure separation, where
required, from traffic below the level of an aircraft joining the ILS or MLS localiser. When a
controller intends to give a pilot successive instructions to establish on a localiser and
descend on a glidepath (ILS/MLS), then the use of “maintain” is not required. Mode C
(when available) shall be monitored until the aircraft is established on the localiser in order
to enable the controller to take appropriate action should the aircraft descend below the
appropriate minimum altitude before following the glidepath. Controllers shall not instruct
pilots to descend on the ILS/MLS when the glidepath intersect would be outside the
glidepath DOC.
9D.3 A complete set of phraseology associated with ILS/MLS approaches is detailed in CAP
413.
Note: MLS provides an ILS look-alike approach and for practical purposes the terms localiser
and glidepath are retained, although an MLS localiser may also be referred to by
alternative terms, e.g. an MLS approach track. Due to the possible confusion between the
words ILS and MLS the word “Microwave” is used to describe an MLS approach in RTF
phraseology and in telephone co-ordination.
9E.2 Aircraft shall be vectored either onto the final approach track, or onto a closing heading
not more than 40° offset from the final approach track to enable the aircraft systems to
complete the turn onto final approach.
9E.3 APV procedures include an Intermediate Fix. The aircraft should be vectored towards the
Intermediate Fix before turning towards the final approach track in order to be on this track
before the Final Approach Point. This will allow the aircraft to cross the Final Approach
Point at the level specified in the notified procedure.
9F.2 Controllers shall vector aircraft onto the final approach track, or onto a heading to close
the final approach track at an angle not greater than 40° offset from the final approach
track. Whenever practicable, the aircraft is to be established on the final approach track
before the Final Approach Fix to enable it to cross the Final Approach Fix at the altitude/
height specified in the notified procedure.
9F.3 For procedures that are not supported by DME, i.e. localiser only, VOR or NDB
approaches, the controller shall pass a range check before clearing the aircraft for the
approach. Additional distance from touchdown information may be passed as necessary
or requested to assist the pilot to follow the published descent profile for the approach.
9F.4 For procedures that are supported by DME, the controller shall pass a range check and
clear the aircraft for the approach when the aircraft is established on the final approach
track.
(1) Standard ATC procedures for sequencing and separating aircraft will apply at all
times during RNAV approaches. Standard IFR separation will be provided for all IFR
traffic.
(2) Pilots will request clearance to fly the procedure. Clearance to fly the procedure
permits the pilot to fly in accordance with the published procedure, following the
descent profile.
(3) The approach commences at the IAF. Pilots may request vectors, where these are
available, for the IAF or may elect to self-position.
(4) Aircraft should normally be cleared to an IAF. Controllers should not issue, and
pilots should not accept, vectors to any point inside the Final Approach Fix at any
time. When necessary for operational or traffic reasons, aircraft may be vectored to
a point on the final approach track no later than the Final Approach Fix. Aircraft to
be vectored to the final approach track in this way must be informed of this
requirement as soon as possible.
(5) Once an approach has commenced, the aircraft should be allowed to self-position
for the approach. Vectors should not then be given unless safety is at risk.
(6) Phraseology associated with RNAV (GNSS) approaches is detailed in CAP 413.
8 miles from touchdown. If landing clearance is not received a subsequent check shall be
made at 4 miles. Clearance to land or alternative instructions received from
Approach/Aerodrome Control shall be passed to the aircraft before it reaches a range of 2
miles from touchdown.
10.2 Where a landing clearance indicator system is installed between the approach radar
controller and aerodrome control, it shall be used for giving clearance to land or missed
approach instructions.
10.3 The indicated surface wind, passed with the landing clearance by Approach/Aerodrome
Control, may be transmitted to the aircraft at the discretion of the approach radar
controller.
11.2 The situation display must clearly indicate the final approach track and ranges from
touchdown. If either of these fail to be indicated, the approach shall be discontinued and
the aircraft instructed to carry out a missed approach if unable to continue visually.
11.3 Aircraft making a radar approach shall be reminded, when on final approach, to check
their gear.
11.4 The ranges at which SRAs terminate will vary according to the Approval. The appropriate
phraseology is in CAP 413.
(1) Advisory heights through which the aircraft should be passing to maintain the
nominal glidepath, together with ranges from touchdown, shall be passed at each
mile;
(2) The pilot shall be instructed to check his minimum descent height one mile before
advisory heights are discontinued;
(3) Advisory heights shall be discontinued at the one above the highest OCH.
(1) Advisory heights through which the aircraft should be passing to maintain the
nominal glidepath, together with ranges from touchdown, shall be passed at each
half mile;
(2) Transmissions shall not be interrupted for intervals of more than 5 seconds from a
range of 4 miles until the approach is terminated;
(3) The pilot shall be instructed to check his minimum descent height at a range of 2
miles;
(4) Advisory heights shall be discontinued at the one above the highest OCH or at 1
mile, whichever is the sooner;
(5) The controller shall not be responsible for any duties other than those strictly
connected with the SRA.
14.2 Advisory levels, that are published in the UK AIP, for SRAs are initially calculated based
either on QNH datum or QFE datum and rounded up to the nearest 10ft. An adjustment is
then made to compute the advisory levels for approaches made using the other datum.
Consequently, for any particular approach, the advisory levels published for the approach
will not necessarily be round values. In order to minimise the potential for misinterpretation
or transposition of digits, unless otherwise requested by the pilot, the advisory levels to be
passed by ATC when conducting an SRA should be rounded up to the nearest 10 feet.
14.3 Advisory levels shall be prefixed with an indication of the datum being used, i.e. “height” or
“altitude”. Pilots conducting an approach based on QNH shall be passed the
aerodrome/threshold elevation prior to commencing the final descent.
14.4 The rounded values to be used when conducting an SRA shall be detailed in MATS Part
2.
(2) When no landing clearance is received before 2 miles from touchdown (or such
other range agreed with Aerodrome Control);
15.2 An aircraft is to be advised to carry out a missed approach in any of the following
circumstances:
(1) If it reaches a position from which it appears that a successful approach cannot be
completed;
(2) If it is not visible on the situation display for any significant interval during the last
two miles of the approach;
(3) If the position or identification of the aircraft is in doubt during any portion of the final
approach.
15.3 Missed approach instructions shall include the level to which the aircraft is to climb and, if
necessary, heading instructions to keep the aircraft within the missed approach area. The
aircraft shall be instructed to contact Approach Control or, by arrangement, to remain with
the approach radar controller.
15.4 In the event of a pilot initiating a missed approach due to a windshear alert generated
from onboard aircraft systems, controllers should be prepared for the aircraft to exceed
the missed approach altitude, and should provide traffic information, instructions, and
advice as deemed appropriate to ensure safety. During such manoeuvres, maximum
thrust is employed and rates of climb will significantly exceed those for missed
approaches executed for other reasons. These high rates of climb, especially when
associated with a missed approach which has a relatively low level-off altitude, can result
in pilots exceeding their cleared level. Aircraft generated windshear alerts also take
precedence over the annunciation of TCAS alerts.
16.2 If the aircraft has not commenced final approach it is to be cleared to an appropriate
facility for an alternative approach, in which case procedural separation shall be provided.
16.3 If the aircraft has commenced final approach, the approach may be continued either
visually or by using an alternative aid, otherwise it is to be cleared for an alternative
approach as above.
17. Departures
17.1 The procedures for the control of departing aircraft by approach radar controllers vary
from unit to unit and shall be detailed in MATS Part 2.
17.2 Departing traffic, which conflict with inbound aircraft receiving an ATS surveillance
service, shall be transferred to the approach radar controller, who shall be responsible for
providing separation, unless authorised procedures automatically ensuring separation are
in operation.
SECTION 3: CHAPTER 3
1. Introduction
1.1 The RVR system has been evolved to make available a more localised assessment of
visual range in relation to a particular runway when the meteorological report gives a
visibility of less than 1500 metres.
The RVR indicates the range over which the pilot of an aircraft on the centreline of a
runway can expect to see the runway surface markings, the lights delineating the runway
or identifying its centreline.
2. Assessment of RVR
2.1 The two methods of RVR assessment available at suitably equipped aerodromes are:
2.2 The UK standard for reporting RVR extends from zero to 1500 metres in the following
steps:
2.3 Not all RVR systems are able to report all increments from zero to 1500 metres. Where
the maximum reportable RVR value for a system and runway combination is less than
1500 metres this information shall be included in the UK AIP.
2.4 Note that any observed value, which does not fit the reporting scale, shall be rounded
down to the nearest step lower in the scale. It is recommended that 50 metres be
regarded as the lower limit and 1500 metres be regarded as the upper limit for
assessments of RVR. Outside of these limits, reports should indicate that RVR is less
than 50 metres or more than 1500 metres.
3.2 Transmissometers are used to measure atmospheric opacity from fixed points alongside a
runway, the number of units in any system being determined by the category of the ILS or
MLS installation and runway length. In a three transmissometer system the units are
linked by an associated data transfer system to a central processor. The processor
computes the RVR for each transmissometer position and displays it in digital form to
ATC. The three transmissometers are located one at each end of the runway adjacent to
the touchdown zone and the third near the runway mid- point area. For RTF transmission
purposes the locations will be known as “Touchdown”, “Mid-Point” and “Stop End” and
RVR values will relate to these positions.
3.3 The system automatically allows for runway edge light intensity settings but the DEO is to
be informed if a controller has reason to believe that the runway lighting is not operating at
the selected level. Additionally the DEO is to be informed if a pilot reports actual
conditions which are significantly different from those being indicated by IRVR methods.
4. System Availability
4.1 IRVR systems are operational at all times unless notified to the contrary by the DEO.
5. Duration of Assessment
5.1 IRVR reporting to aircraft is started:
(1) whenever the aerodrome meteorological report shows the visibility to be less than
1500 metres;
(2) whenever the IRVR display is indicating an RVR value equal to or less than the
maximum for that system;
(3) whenever shallow fog is reported and during a period for which it is forecast.
6. IRVR Indications
6.1 A number of different IRVR systems are installed at UK aerodromes. The processors in
some systems are programmed to automatically reduce in intensity, or suppress, the
display of the mid-point and/or stop-end readings when the values are not operationally
significant.
6.2 Unless a suppressed value is specifically requested by a pilot, the RVR reports
transmitted are to contain only those values that are displayed at full intensity. The value
of the touchdown position is always displayed at full intensity and if no other values are at
full intensity this is the only value which needs to be passed.
6.3 A description of the equipment, its use and any other associated liaison with the DEO
shall be included in MATS Part 2.
7. Transmission to Aircraft
7.1 IRVR values are to be passed to aircraft at the beginning of each approach for landing
and, thereafter, whenever there is a significant change in the RVR until the aircraft have
landed. A significant change is defined as a change in value of one increment or more.
The current RVR value is also to be passed to aircraft before take-off.
7.2 Even though a pilot may have received an IRVR value from the ATIS broadcast,
controllers must ensure that they pass the current value as specified above.
7.3 When all three positions are to be reported to the pilot, they are to be passed as three
numbers relating to touchdown, mid-point and stop end respectively, e.g.
7.4 If only two values are to be passed, they are to be individually identified, e.g.
7.5 A high degree of priority should be given to such broadcasts to ensure that current RVR
information is provided to pilots with the minimum delay.
8. Transmissometer Unserviceability
8.1 If the touchdown transmissometer fails, the IRVR system may still be serviceable provided
that confirmation is received from the DEO to this effect. In such circumstances the mid-
point value is to be used to determine the ATC procedure and is to be passed to the pilot
together with the stop end value, if this is available. It is imperative that the pilot should be
informed that the touchdown transmissometer has failed, e.g.
“RVR runway (designator) Touchdown not available — Mid-Point 600 — Stop End 400
metres”.
8.2 If two transmissometers become unserviceable the RVR value for the remaining
instrument provided that it is not the stop end value, may be used. If the RVR value for the
stop end is the only one available, the system is to be regarded as unserviceable for that
runway. By changing the direction of use of the runway it may become serviceable again
with the single available value representing the touchdown reading.
8.3 When the IRVR system is unserviceable, controllers should revert to Human Observer
RVR where provided, or to the reported meteorological visibility to determine ATC
procedures. In the latter case, pilots should be passed the reported meteorological
visibility and advised that the IRVR system has failed.
9.2 Under no circumstances shall RVR be assessed from a position on the runway.
9.3 The number of runway edge lights visible is to be applied to a conversion table to obtain
the RVR value. Detailed procedures of the method of calculation shall be included in
MATS Part 2.
9A.2 In the event that an RVR measurement cannot be made, the pilot should be passed the
meteorological visibility and advised that RVR is not available.
9B.2 RVR reports are not to be used or passed after the observer has been stood down, except
when that report is quoted as part of a full meteorological report including a time or origin.
(1) to inbound aircraft, before the commencement of approach until the aircraft has
landed;
9C.2 A high degree of priority should be given to such broadcasts to ensure that current RVR
information is provided to pilots with the minimum of delay.
9D. Limitations
9D.1 Only RVR incremental values up to the maximum reportable value are to be passed to
aircraft. The maximum reportable value for a particular runway shall be indicated in MATS
Part 2.
9D.2 If the assessed value is more than the maximum reportable value, controllers are to state
“RVR is greater than (number) metres”.
9D.3 If no lights are visible, controllers are to state “RVR less than (number) metres”, inserting
the value corresponding to one light.
10. General
10B.2 However with some IRVR equipment, because of the design of the system,
transmissometer readings may only be displayed when the runway lights are set at an
intensity of 10% or more. Settings less than 10% may result in all three readings being
replaced by zeros. If, during RVR conditions, a pilot requests a reduced runway edge light
setting of less than 10%, he is to be advised that an RVR reading may not be available at
this setting.
10B.3 RVR human observer assessments are not to be made with the lights set at an intensity
for which there is no conversion table. If a pilot should request that the lights be reduced
in intensity and this results in a setting for which there is no conversion table, the pilot is to
be advised that RVR is not available at this requested setting.
10C.2 For records of Human Observer RVR the following minimum information shall be
recorded:
(1) Aerodrome;
(2) Date;
(3) Runway;
(5) The time each observation is logged, expressed in UTC to the nearest minute;
(6) The actual count expressed as the number of lights observed, e.g. ‘Four lights’, and
the corresponding RVR value.
SECTION 4: CHAPTER 1
1. Provision of Services
1.1 Area Control Services within the UK FIRs comprise surveillance and non-surveillance
based air traffic services in airspace not under the jurisdiction of an approach or
aerodrome control unit.
1.2 The type of service to be provided will depend on the class of airspace within which the
aircraft is flying as tabulated below:
Table 1:
2. Units
2.1 An ACC is established in each FIR to provide an Area Control Service in the airspace
under its jurisdiction.
SECTION 4: CHAPTER 2
1. Principles of Operation
1.1 An ACC is divided into sectors, which work in close liaison. The method of operation
differs at each centre but will always be based on the following principles:
(1) Each controller shall be responsible only for the efficient performance of those tasks
that are specifically allocated in the task description. Tasks are detailed in MATS
Part 2;
(2) Controllers are to monitor the actions of other members of the sector team to the
extent that prime duties permit;
(3) Sectors must have a defined prime flight data display for the purpose of conflict
detection, which should at all times reflect all clearance instructions issued and
communications received;
(4) Inter-sector co-ordination purposes require laid down criteria which enable the co-
ordinator, when authorised by the CAA, to use surveillance derived information for
the transfer of traffic between sectors without reference to the controller.
2.2 The complete process of co-ordination, which must precede transfer of control, has been
achieved when:
(1) notification, negotiation and agreement has taken place progressively, i.e. step by
step;
(2) it has been agreed that aircraft can proceed under specified conditions without the
need for individual co-ordination. The principles of such agreements and controllers’
positions to which they apply shall be detailed in MATS Part 2;
(3) an estimate message has been passed and no objection has been raised by the
accepting ATC unit. This procedure must be approved by the CAA.
2A. Revisions
2A.1 Subsequent changes in flight level, routeing or revisions of 3 minutes or more are to be re-
co-ordinated by the transferring controller and agreement reached before transfer of
communication takes place.
(1) Lowest level at the holding point available for use by Area Control;
(4) Arrival times over the holding point if these vary from the estimate by 3 minutes or
more;
(5) Missed approaches when re-routeing is entailed, so that subsequent action is co-
ordinated;
3A.2 The passing of any of this information may be delegated from Approach to Aerodrome
Control. Any of these items can be deleted from routine practice by agreement with Area
Control.
3C.2 Release messages shall be passed to Approach Control in a timely manner as specified
in unit (MATS Part 2) procedures and shall contain the following:
(4) Estimated time and level at the holding facility, or arrival time and level at holding
facility if the release is given after arrival;
3C.3 Aircraft released to Approach Control must be within controlled or advisory airspace when
the release becomes effective. All other aircraft at lower levels must also be released or
procedural separation provided. Aircraft released to Approach Control shall not be levelled
off, or climbed, above the level at the holding facility passed in the release message
without co-ordination with Area Control.
3C.4 Unless approved by the CAA, the release point of aircraft released to Approach Control
shall be below FL195. When such procedures are approved by the CAA, MATS Part 2
shall include details of the area in which aircraft may be released and the full details of the
conditions under which the procedures may be used.
3C.7 Area Control may, after co-ordination with Approach Control, clear an arriving aircraft to
an aerodrome holding facility, or to a visual holding point, instead of the normal holding
facility.
(1) The outbound clearance is qualified by “Release subject your discretion” together
with details of the conflicting traffic; and
(2) The release message on the inbound aircraft, or full details of the overflying traffic,
have already been passed.
3D.2 An RSYD restriction is intended to facilitate the overall expedition of traffic where
Approach Control procedures may offer a more expeditious resolution of the confliction
than Area Control procedures. It is the responsibility of the approach controller to
determine whether he can provide the required separation in order to clear the outbound
aircraft for departure. Before the outbound aircraft is transferred to Area Control, all
conflictions must have been resolved or co-ordination effected.
3E.2 An ACC may issue two clearances to an Approach Control unit and request that an
aerodrome separation is applied between the aircraft. In such cases the telephone
phraseology used would be “.... release subject (callsign)”. Under such circumstances,
before transfer of control takes place, the second aircraft to depart shall be separated
from the first departure. In such cases the approach controller must ensure that
separation between the two aircraft is constant or increasing. If the approach controller is
unable to achieve this the centre must be advised immediately and a new course of action
agreed.
4. Responsibilities
4.1 Area Control is responsible for providing separation between aircraft operating in
controlled or advisory airspace, in accordance with the airspace classification and aircraft
flight rules, and ATC clearances to aircraft shall be based solely on the requirements for
providing ATC services within such airspace.
4.2 The area within which ATS surveillance services are provided is determined by the
coverage of the equipment but may be further limited to areas defined in MATS Part 2.
4.3 Where authorised, Area Control may on a permanent or limited basis, provide ATS in
airspace normally the province of another control unit. The particular arrangements for
each ACC shall be published in MATS Part 2.
5. Separation
(1) When authorised procedures are in operation whereby the known traffic is under the
control of another controller, who is utilising an ATS surveillance system, and
separation can be maintained by direct co-ordination; or
(2) When authorised procedures are in operation whereby track or vertical separation is
deemed to exist.
Vertical separation must be provided at least 10 miles before the point at which the
conflicting traffic can be expected to enter PSR/SSR cover;
Proceeding into PSR/SSR cover, vertical separation must be provided until the
identified aircraft is at least 10 miles within the point at which the conflicting traffic
can be expected to enter coverage.
7. Position Reports
7.1 In order to reduce RTF communication, a pilot will make a position report only:
(1) on first transfer of communication from another ACC or sector. This report will
contain aircraft identification and flight level only. Subsequent reports will contain
aircraft identification, position and time;
9.3 Receipt of flight plan data does not constitute a clearance, except that when ATC has
acknowledged receipt of the information from an aircraft in flight and radio failure occurs
before a clearance can be transmitted, the aircraft may be expected to proceed in
accordance with the flight plan. Aircraft should be given a clearance in reply to an in-flight
request, but if this is not possible the aircraft are to be advised to remain outside
controlled airspace, when to expect clearance and given a time check.
9.4 In considering requests for crossing or joining clearances it should be remembered that an
aircraft already cleared to operate at a level within controlled airspace has prior claim to
that level.
9.5 Pilots of aircraft that cannot comply with the full IFR are permitted to request clearances to
cross airways in VMC by day. However, controllers are to handle these requests as
though they are IFR flights.
9.6 No clearance is required for an aircraft to fly at right angles across the base of an airway
where the base is defined as a flight level. In VMC by day, gliders may cross certain
airways without clearance. Details appear in the UK AIP (ENR) section.
10.2 Military aircraft will either obtain a clearance to cross an airway or will cross under military
radar control, whereby separation, either horizontal or vertical or both, between the
crossing aircraft and airways traffic is provided without reference to the civil controller.
Requests for crossing clearances will be made to a chief sector controller or executive
sector controller direct or by arrangement through the civil controller. The procedure is
entirely at the discretion of the civil controllers and shall be granted only if work load
permits and adequate communication facilities are available.
10.3 In an emergency, where no crossing clearance can be obtained, military aircraft may
cross an airway at an intermediate 500 feet level in order to provide vertical separation
from airway cruising levels. The intermediate 500 feet levels referred to are fl levels of
whole thousands plus 500 feet.
11.2 Aircraft which will be delayed by 20 minutes or more before commencing an intermediate
approach for landing shall be given an expected approach time together with their
clearance to the holding facility. If an aircraft is likely to be delayed less than 20 minutes
no expected approach time is to be passed. If the pilot requests the delay he shall be
informed that the delay is expected to be less than 20 minutes.
11.3 Procedures for aircraft waiting for approach clearance when the delay cannot be
determined are described in Section 1, Chapter 4.
12. Diversion
12.1 In the majority of cases, it shall be the responsibility of the Watch Supervisor at the ACC
to make arrangements for the diversion of aircraft. When weather indicates a possibility of
diversions he shall:
(1) keep a close watch on the weather at aerodromes in his area and ensure that
arriving aircraft have the latest information;
(2) anticipate which aerodromes are likely to be the most suitable according to:
(3) check that diversions can be accepted and note any particular arrangements the
aerodrome may require.
(1) give the aircraft a diversion message containing the latest weather information,
clearance instructions, radio frequencies to be used, etc.;
(2) give full information to the diversion aerodrome, including details of the aircraft, its
clearance instructions, etc.;
SECTION 4: CHAPTER 3
1. Introduction
1.1 FISOs at ACCs provide a Basic Service to aircraft from dedicated positions and on
discrete frequencies. This service is provided by London/Scottish Information within
airspace and during periods that are notified in the UK AIP.
1.2 Controllers provide a Basic Service to aircraft outside this airspace and within this
airspace outside the notified periods of operation when the service is provided by FISOs.
When carrying out co-ordination, controllers shall distinguish between their ATC and
London Information roles.
1.3 Detailed procedures for FISOs at ACCs are contained in the unit MATS Part 2 and other
FISO documentation. Some of the guidance in this chapter also applies to FISOs but, for
simplicity, the text will refer only to controllers performing the London/ Scottish Information
role.
2. Limiting Factors
2.1 Factors limiting the air traffic services given by controllers providing a FIS include the
following:
(1) Civil and military aircraft may fly on random tracks with consequent multiplicity of
reporting points;
(3) Absence of accurate navigation and associated position fixing may cause unreliable
position reporting and estimates;
(4) The size of the sectors makes it difficult for controllers to be aware of the many
geographic locations used and their proximity to each other;
(5) Even when flight plan information is known to the controller he frequently has no
indication as to whether such aircraft are adhering to planned routes, altitudes and
timings;
(6) RTF coverage may not be available in all parts of the unit’s airspace.
2.2 Because accurate assessment of collision risk is doubtful, it is recognised that no form of
control or separation can be provided.
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3. Proximity Warnings
3.1 When it is self-evident from the amount and accuracy of the information presented by
pilots in receipt of a Basic Service, controllers, when practicable, should provide
supplementary warnings related to the proximity of the subject aircraft. In particular,
warnings should be issued to aircraft which are, or may become, in dangerous proximity
to each other. For other situations, controllers may inform a pilot of the presence or
absence of traffic as indicated to them. It is recognised that the provision of proximity
warnings and traffic information may be based on data of doubtful accuracy and
completeness. The decision to make any alteration to the flight remains with the pilot and
traffic avoidance advice shall not be issued.
Table 1:
Regional Pressure Setting (hPa) Minimum Flight Level (500 feet separation)
1032 or above FL30
1031 – 1014 FL35
1013 – 996 FL40
995 – 978 FL45
977 – 960 FL50
959 – 943 FL55
942 – 927 FL60
Table 2:
(2) Aircraft reports at the boundary or Advise aircraft to contact the appropriate ATSU
details had not been passed. in the adjacent FIR.
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5.2 Scottish Information task does not imply any SAR obligation. In this regard, controllers are
not to take action in the case of an aircraft failing to establish communication after an
estimate has been received.
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SECTION 4: CHAPTER 4
1. Introduction
1.1 This section contains a general outline of those procedures relating to Oceanic Control
that are relevant to controllers operating sectors in adjacent domestic airspace. More
detailed procedures for Oceanic Area controllers are contained in MATS Part 2.
1.2 Shanwick OAC (Prestwick) provides Area Control, ICAO Standard FIS and Alerting
Services to aircraft operating within the Shanwick OCA.
1.3 The oceanic controller is assisted in this task by the use of an FDPS, which carries out
conflict prediction and detection, automatic update of flight profiles and data transfer to
online adjacent units.
1.4 The vertical limits of the Shanwick OCA are from FL55 with no upper limit. Throughout the
control area, airspace at and above FL55 is notified as Class A. VMC climbs or descents
are not permitted.
2A.2 Aircraft unable to contact “Shanwick Oceanic” on VHF should request clearance on North
Atlantic en route HF RTF Network (NARTEL) at least 40 minutes before the ETA for the
oceanic boundary and thereafter maintain a SELCAL (Selective Call) watch for receipt of
the oceanic clearance.
2A.3 While in communication with Shanwick for oceanic clearance, aircraft must also maintain
communication with the ATC authority for the airspace in which they are operating.
(1) callsign;
(4) if the aircraft is required to report meteorological information in flight, the phrase
“Send Met reports”.
2D.3 The Mach number shall be included in each clearance given to subsonic turbo-jet aircraft
operating within Gander, New York, Reykjavik, Santa Maria and Shanwick OCAs.
3.2 Shanwick is responsible for establishing and publishing the westbound tracks and Gander
the eastbounds. Westbounds are allocated the designators A to M and the eastbound
tracks N to Z, excluding the letters I and O.
3A.3 The track signal shall be despatched at least 8 hours in advance of their period of
operation. Any subsequent changes in the structure shall be notified as soon as
practicable.
4A.2 Both horizontal and longitudinal separation minima in certain circumstances are greater
than standard domestic separation. The separation minima for the Shanwick OCA
applicable to aircraft at the time they cross the oceanic/domestic airspace boundary are
as stated in MATS Part 2.
SECTION 4: CHAPTER 5
Meteorological Information
1. Supply of Information
1.1 Meteorological information supplied to ACCs is summarised below. Details of the
information supplied by the Meteorological Office is contained in Section 7. Runway visual
range is described in Section 3.
Table 1:
3. Transmission to Aircraft
3.1 Either of the following methods may be used to pass meteorological information to aircraft
in flight:
3.2 Controllers must ensure that information transmitted to flights conforms to that which is
requested (e.g. a report should not be given in place of a forecast).
3.3 SIGMET messages should be relayed with the least possible delay to all aircraft likely to
be affected but without prejudice to control of aircraft in flight.
3.4 RVR values are to be transmitted when requested by pilots or at the discretion of the
controller.
3.5 As a general rule, controllers shall only transmit meteorological information to aircraft that
has been supplied, or agreed by, the Meteorological Office. The exceptions are detailed in
Section 3, Chapter 1.
SECTION 4: CHAPTER 6
1. Operating Procedures
1A. Definition
1A.1 A Temporary Reserved Area is a defined volume of airspace normally under the
jurisdiction of one aviation authority and temporarily reserved, by common agreement, for
the specific use by another aviation authority and through which other traffic may be
allowed to transit under an ATS authority.
1A.2 Detailed access arrangements for TRAs are notified in civil and military AIPs. The
airspace within an activated TRA shall be treated as uncontrolled and ATS shall be
provided on the basis of services to aircraft outside controlled airspace. Aircraft in receipt
of an ATS surveillance service shall be provided with advice or information appropriate to
the service being received.
1A.3 The dimensions and activation times of TRAs are defined in the UK AIP. Charts of the
airspace structure arrangements between FL195 and FL245 are also notified in the UK
AIP.
1A.4 TRAs may overlap other airspace structures such as Danger Areas. In such
circumstances, the airspace structure with the more restrictive access criteria or rules will
take precedence.
1A.5 Operations within an activated TRA should be conducted on standard pressure setting,
1013.2 hPa.
1A.6 Within an activated TRA between FL195 and FL245, the semi-circular cruising level
system shall be applied.
1A.7 Controllers should be aware that military aircraft operating autonomously in an activated
TRA will squawk 7006. Where the TRA is contiguous with controlled airspace, pilots
operating autonomously have been requested to aim to operate no closer to the lateral
boundary than 3 miles or within 500 feet of the vertical limit of that TRA.
1B. Gliders
1B.1 Some TRAs have been established for sole use by gliders. These shall be identified by
the acronym TRA(G). Access arrangements to TRA(G)s will be detailed in the UK AIP and
flights will be conducted in accordance with the appropriate LoA arrangements. Gliders
without transponders shall only operate above FL195 when within an activated TRA(G).
Specific rules for non-SSR equipped gliders operating in a TRA(G) will be detailed in the
respective LoA.
1B.2 Except for Air Defence Priority Flights and aircraft in an emergency, IFR traffic shall not be
cleared to transit through an activated TRA(G).
1C.2 Civil aircraft flying VFR and seeking to access an activated TRA shall:
(2) file a flight plan (when specified, an abbreviated flight plan will be acceptable – see
Section 1, Chapter 2, paragraph 9A.1 sub-paragraph (1);
(3) obtain an ATC clearance to enter the TRA. IFR aircraft requiring transit through a
TRA to or from adjacent controlled airspace will already be in receipt of an ATC
service and will not require an additional ATC clearance;
2. Collision Avoidance
2.1 The pilots of aircraft operating within an activated TRA are responsible for avoiding
collisions in accordance with the Rules of the Air.
2.3 Aircraft operating within an activated TRA and receiving a Deconfliction Service or Traffic
Service will be advised of the proximity of aircraft operating within adjacent Class C
airspace.
3.2 Specified approved military ATS units may be authorised by the CAA to provide ATS
within an activated TRA up to FL245 in accordance with the conditions of the Approval.
3.3 Unless otherwise approved by the CAA, the provision of ATS by civil Approach units shall
only be permitted below FL195.
(1) Civil ACC controllers are responsible for all aircraft operating on an ATS route.
(2) The MoD is responsible for military aircraft not operating on an ATS route and may
be responsible for civil aircraft operating off-route, including within activated TRAs,
as detailed in the Manual of Military Air Traffic Management (MMATM) and unit
order books.
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SECTION 5: CHAPTER 1
Aircraft Emergencies
1. Introduction
1.1 The circumstances of each aircraft emergency can vary to such an extent that detailed
instructions cannot be given for every situation. The procedures outlined in this section
are intended as a general guide and controllers must use their own judgement when
handling a particular emergency.
(4) When an air traffic services unit knows or believes that an aircraft is being subjected
to unlawful interference, no reference shall be made in ATS air-ground
communications to the nature of the emergency unless it has first been referred to in
communications from the aircraft involved and it is certain that such reference will
not aggravate the situation (SERA.10005(b)).
Note 1: An aircraft which is being subject to unlawful interference shall endeavour to set the
transponder to Code 7500 and notify the appropriate ATS unit of any significant
circumstances associated therewith and any deviation from the current flight plan
necessitated by the circumstances, in order to enable the ATS unit to give priority to the
aircraft and to minimise conflict with other aircraft (SERA.10005(ab)).
Note 2: If an aircraft is subject to unlawful interference, the pilot-in-command shall attempt to land
as soon as practicable at the nearest suitable aerodrome or at a dedicated aerodrome
assigned by the competent authority, unless considerations aboard the aircraft dictate
otherwise (SERA.11005(ab)).
1.3 The procedures described in the preceding sections and the appropriate standard
phraseology may also be varied to meet an emergency situation but any reduction in
separation, necessary to cope with the emergency, should be restored as soon as
possible. Special arrangements, made locally for handling aircraft emergencies, are
detailed in MATS Part 2.
1.4 In addition to the procedures outlined below, CAP 745 Aircraft Emergencies –
Considerations for Air Traffic Controllers, is available to give further guidance on handling
emergency situations.
2. Controllers Responsibility
2.1 Controllers must always be alert to the possibility of an aircraft emergency. Speed may be
necessary in certain circumstances but calm co-ordinated actions are essential in all
situations.
2.2 Controllers shall offer as much assistance as possible to any aircraft that is considered to
be in an emergency situation. Assistance to the aircraft can include the provision of
information on the availability of aerodromes and their associated approach aids,
vectoring, weather information and details of terrain clearance. An emergency may require
alerting action to be taken immediately or it may develop to that point later.
2.3 The supervisor, if available, should be informed as soon as practicable and where more
than one ATSU is involved complete co-ordination must be maintained between units.
2.4 If the ACC is involved the ACC supervisor should take charge of the operation. Controllers
must be ready to give all possible assistance to the ACC, ARCC and other units. If more
than one ACC is involved then the supervisors should agree between them which one
takes charge.
2.6 The Alerting Service is described in Chapter 6 and the aerodrome emergency service in
Chapter 7.
(3) a pilot makes a report about the malfunctioning of his aircraft or the unusual
behaviour of persons on-board;
3.2 If the controller is in radio contact with the aircraft he should ask the pilot if he wishes to
declare an emergency and, if not specified by the pilot, the class of emergency being
declared.
3.3 More positive indications that an aircraft is in an emergency are described in the following
paragraphs.
4.3 The message will contain as many as possible of the following items:
PAN PAN, PAN PAN, PAN PAN (for urgency messages); and
(2) Name of the station addressed (time and circumstances permitting) Identification of
the aircraft;
(4) Intention of the person in command Present position, level and heading;
(5) Qualification of the pilot e.g. Student, IMC or full instrument rating (urgency
messages); and
4.4 If the position is stated in terms of LORAN co-ordinates, the RCC will convert it to latitude
and longitude at the request of the ACC supervisor.
4.5 When a pilot has given certain items of information normally associated with an
emergency message but has not prefixed the transmission with ‘MAYDAY’ or ‘PAN’, the
controller is to ask the pilot if he wishes to declare an emergency. If the pilot declines to
do so, the controller may, if he thinks it appropriate, carry out the necessary actions as if
the pilot had declared an emergency. The term ‘fuel emergency’ has no status in the UK
and controllers are not required to give priority to aircraft with a reported shortage of fuel
unless an emergency is declared.
4.6 If a controller considers that another ATSU may be able to give more assistance and, in
the circumstances, it is reasonable to do so, the pilot should be asked to change
frequency.
(2) A succession of pyrotechnical lights fired at short intervals, each showing a single
red light;
(1) for an aircraft in difficulties that compel it to land without requiring assistance, the
following signals:
(2) For an aircraft with a very urgent message to transmit concerning the safety of an
aircraft (including that sending the message), a ship or person, the signal XXX with
signalling apparatus.
(3) Code 75 (7500) – Hijack or Other Act of Violence (see Chapter 5).
6.2 To indicate an emergency condition pilots are encouraged to select Code 7700 as soon
as is practicable after declaring an emergency situation, having due regard for the
overriding importance of controlling aircraft and containing the emergency.
6.3 However, if the aircraft is already transmitting a discrete code and receiving an air traffic
service, that code may be retained at the discretion of either the pilot or the controller.
7.2 The aircraft fly at least two triangular patterns, before resuming course, as follows:
Table 1:
Transmitter Failure
Aircraft Speed Length of Leg Complete Failure
Only
300 knots or less 2 minutes
Right hand turns Left hand turns
More than 300 knots 1 minute
7.3 If a triangular pattern is observed, controllers shall advise the D&D cell of the position and
track and continue to plot the aircraft whilst it is within ATS surveillance system cover.
Controllers should also be aware of the effect wind may have on the pilot’s ability to fly an
accurate triangle.
8.1 On receipt of information that indicates that an aircraft is in an emergency, the controller
must decide whether or not to transfer the aircraft to another agency. The choice of
agency will depend upon the circumstances and no hard and fast rules apply. The
following guidance material will help controllers to make this decision.
8A.2 Alternatively it may be more expedient to transfer the emergency aircraft to a discrete
frequency, particularly if a radio silence would endanger other traffic.
8A.3 The aircraft should be retained on the original frequency if it is unreasonable to ask the
pilot, or if he is not prepared, to change frequency. The controller may be able to relay
instructions and information from other units to the pilot.
(1) consult the ACC supervisor and transfer the aircraft according to his instructions; or
(2) alert the nearest suitable unit and transfer the aircraft to a common frequency, giving
assistance to that unit as required.
8B.2 Before transferring aircraft, controllers should obtain sufficient information from the pilot to
be convinced that the aircraft will receive more assistance from another unit. If a change
of frequency is desirable the pilot must be instructed to revert immediately if there is no
reply on the new frequency. Controllers should then listen out on the original frequency
until the aircraft is known to be in two-way communication with the other unit.
D&D use the terms ‘Executive Control’ and ‘Operational Control.’ If an aircraft calls
on 121.5 MHz, the D&D controller has both executive and operational control. Once
D&D hand the aircraft to another unit they pass-over Operational Control but retain
Executive Control. This means that D&D do not give up all responsibility for an
emergency once the aircraft is working another unit. They retain responsibility for
overall management until the emergency ends.
D&D controllers only have access to the Area Control ATS surveillance systems at
their parent unit, which may have poor low level coverage, therefore a D&D
controller may seek an early handover to the aerodrome ATSU in order to avoid the
need to stop the descent of an emergency aircraft.
D&D controllers do not have a detailed knowledge of the local airspace, terrain or
obstacles surrounding aerodromes. Therefore the D&D controller may require
guidance on local Minimum Sector Altitudes in order to provide the fullest possible
service to actual emergencies.
D&D’s low level radio coverage (below 3000 feet amsl) is poor and so an early
handover to the diversion aerodrome may be sought by the D&D controller. In
certain circumstances, e.g. A UHF-only equipped aircraft diverting to a VHF-only
equipped aerodrome ATSU, it may be impossible to transfer RTF communications
with the aircraft to its destination aerodrome. In these circumstances the D&D
controller may request that the control of the aircraft be transferred to the aerodrome
ATSU, which would necessitate all subsequent control instructions being passed on
the telephone, through the D&D controller, for relay to the pilot. It is imperative when
this happens that controllers are agreed as to who is responsible for the control of
the aircraft. Additionally, the aircraft may initially need to be kept high and/or very
early landing clearances passed to the pilot, so that all necessary control
instructions are completed before loss of RTF occurs.
9.2 D&D controllers have a detailed knowledge of minor aerodrome availability within their
area as well as a comprehensive database that enables rapid communication with
aerodromes, Aircraft Operators, ATSUs, and the SAR organisation including Police Air
Support Units and the regional emergency services. The D&D cell can assist a pilot of an
aircraft in an emergency and the civil ATSU to select the most suitable diversion
aerodrome. The D&D cell also provide facilities for practising emergency procedures to
both civil and military pilots.
9.3 The D&D cell at Swanwick can provide an instant VHF auto-triangulation fixing service on
121.5 MHz. This service is only available to aircraft operating over land south of the river
Humber and east of Airway N864 at and above 3000 feet amsl and at and above 2000
feet amsl within 40 nm of Heathrow. A manual fixing service is available outside this area
throughout both FIRs, where there is a reasonable possibility of fixing the position of an
aircraft transmitting on 121.5 MHz at 3000 feet and above over the UK land area and
coastal waters. However, in mountainous areas, coverage at lower levels will be adversely
affected.
9.4 Successful VDF fixing also depends to a great extent upon the quality of additional
information that the pilot and controller can give to the D&D cell.
10.2 In addition, if it appears that the message is not being acknowledged the controller shall:
(1) forward the message to the station being called and/or the ACC supervisor;
11A.2 Emergency Orders should detail that the local emergency services are also informed,
even if the aircraft is within the agreed response radius of the Aerodrome Fire Service.
This response radius could be considerable in terms of distance. Depending upon where
the incident occurs, the local emergency services may be closer to the incident area and,
if first to arrive, could assist by passing the exact location to the responding Aerodrome
Fire Service.
11A.3 If it is doubtful that an aircraft can reach an aerodrome, the Distress phase exists. The
ACC supervisor must be informed so that he can take alerting action with the RCC.
11B.2 Notify the aerodrome selected for emergency landing so that it can make suitable
preparations.
11B.3 Warn other aerodromes in the vicinity and on track to stand by. This can most easily be
done through the ACC supervisor.
11B.4 When it is known that the emergency aircraft is committed to landing at the selected
aerodrome, units shall, in conjunction with any other appropriate ATSUs, give
consideration to the sterilization of the landing runway.
11C.2 It may be advisable to plot the position and track on a map. VDF can be used to fix the
position by obtaining bearings from other units having the same frequency.
11C.3 Controllers should always pass position and bearing information about an emergency
aircraft to other interested units; particularly the ACC.
11E.2 Due to high flight deck workload, the first indication to a controller that an aircraft is
carrying out an emergency descent may be an unexpected change in level on the
situation display. However, the pilot may be able to make a short RTF broadcast, and
should select the emergency SSR code 7700.
11E.4 ICAO Doc 7030/EUR states that an aircraft shall, if able, initiate a turn away from the
assigned route or track before commencing the emergency descent. However, due to the
complex and congested UK controlled airspace, pilots flying in UK FIRs have been
instructed that they should, if able, remain on the assigned route or track whilst carrying
out the emergency descent; unless to do so would endanger the aircraft. Ultimately it is
the pilot’s responsibility to take the action most appropriate in the circumstances.
Consequently, controllers must remain alert to the potential for aircraft conducting an
emergency descent to change heading without notice and be ready to provide appropriate
instructions and information to aircraft in proximity.
11E.5 The controller’s priority is to provide separation from all conflicting traffic on the
emergency descent aircraft’s track, issuing traffic information as appropriate. A rapid
descent will cause the aircraft to pass through numerous sectors very quickly; therefore,
co-ordination with adjacent sectors and even other control centres is essential. Primarily,
controllers should ensure that separation is maintained by turning other aircraft away from
the aircraft conducting the emergency descent. However, if necessary, controllers may, as
required by the situation, suggest a heading to be flown, if able, by the aircraft carrying out
the emergency descent in order to achieve separation from other aircraft concerned.
However, controllers should remember that they may not be fully aware of any particular
handling difficulties the aircraft may have.
11E.6 When deemed necessary, controllers may broadcast an emergency message, or cause
such message to be broadcast, to alert all other aircraft of the emergency descent. The
emergency broadcast message should contain instructions for specific actions to be taken
by aircraft addressed in the broadcast or, alternatively, instructions to continue in
accordance with their current clearances, and to stand by on the appropriate channels for
further clearances and instructions. Controllers should be aware that ICAO Doc 4444
states that aircraft receiving an emergency descent broadcast will clear the specified
areas and then standby on the appropriate radio frequency for further clearances from the
ATC unit. Consequently, in the absence of specific instructions provided to the aircraft
addressed in the broadcast, it may be expected that such aircraft will clear the area on
their own initiative.
(1) Co-ordinating the operation unless immediately effective action can be taken at the
originating unit.
11H.2 A message from the operator, e.g. bomb warning, suspected damage to airframe, etc, is
to be passed to the commander immediately using the operator’s own words. A message,
which has to be relayed via an ACC outside the UK, must be confirmed with a priority SS
signal and addressed to the aircraft.
11I.2 The decision to comply with advice or instructions to land at an aerodrome, other than his
selected diversion, lies with the captain of the aircraft who has ultimate responsibility for
the safety of his aircraft.
11I.3 It is desirable that aircraft in an emergency should not be routed over densely populated
areas, particularly if there is reason to believe that the aircraft’s ability to remain in
controlled flight is compromised or that parts of the aircraft could detach in flight. If this is
inconsistent with providing the most appropriate service to the aircraft, for example when
any extended routeing could further jeopardise the safety of the aircraft, the most
expeditious route is the one that should be given. Where possible, when expeditious
routeing is not required, suggestions of alternative runways or aerodromes together with
the rationale that the routeing would avoid densely populated areas and be consistent with
safety, shall be passed to the pilot and his intentions requested.
11I.4 It is recognised that controllers providing en route services at ACCs may not be aware of
the boundaries of major cities, towns or villages. However, controllers providing
aerodrome, approach or approach radar control services should be familiar with the
centres of population within their areas of jurisdiction.
11I.5 Controllers should be aware that aircraft experiencing engine failure may also experience
associated handling difficulties and should therefore limit manoeuvring instructions to the
minimum necessary.
11J.2 ICAO requires the pilot to give information about the dangerous goods to the ATSU either
in full detail, as a summary or by providing to a telephone number of the location from
where this detailed information can be obtained immediately. Therefore, when a pilot
intends to provide an ATSU with dangerous goods information, controllers should, as the
preferred option, request the pilot to provide a telephone number from where detailed
information can be obtained.
11J.3 However, it is possible that the pilot might not be able to provide this telephone number
and therefore, controllers should then request the pilot to provide a summary of the
quantities and classes or divisions of dangerous goods carried, as receipt and
transcription of full details of voluminous and technically detailed chemical information
would be impracticable.
11J.4 It is important that all details provided by the pilot are passed, without delay, to the
relevant emergency services.
11J.5 In the event that an aircraft that is known to be carrying dangerous goods has crashed, all
pertinent information, including that relating to the dangerous goods carried on the aircraft,
shall be passed to the Senior Fire Officer (or the Fire Service Incident Commander or
Senior Police Officer) at the accident site without delay. Where the crash occurs whilst the
aircraft is en-route, the ACC Watch Supervisor shall pass this information to the relevant
emergency services without delay.
11J.6 Notification of dangerous goods will not always be found on the flight plan. Whilst this may
be so on some occasions, many aircraft will be carrying dangerous goods as cargo of
some sort and the absence of an annotation on the flight plan should not be taken as an
indication that no dangerous goods are being carried.
(2) Prestwick.
11K.2 Other civilian aerodromes may be suitable subject to the type and quantity of explosive
being carried and consequently, if the situation permits, the agreement of the Aerodrome
Operator should be sought. Heathrow, Gatwick and Manchester should not be considered
as suitable diversion aerodromes for emergency aircraft specifically carrying explosives
under an exemption issued by the CAA.
11K.3 Operators of aircraft carrying explosives under an exemption issued by the CAA are
required to insert, on the aircraft’s flight plan, a telephone number from where detailed
information concerning the explosives carried can be obtained. This telephone number will
be found in item 18 immediately after the Operator descriptor e.g. OPR/ (operator name)
Tel: +(country code) (telephone number).
13.2 When an aircraft in controlled airspace needs to dump fuel, ATC should co-ordinate with
the flight crew:
(1) the route to be flown which, if possible, should be clear of cities and towns,
preferably over water and away from areas where thunderstorms have been
reported or are expected;
13.3 Controllers are to recommend to flight crew that jettisoning of fuel should be carried out
above 10,000 feet agl. Exceptionally, if fuel dumping at this level, or over water, is
operationally impracticable or inconsistent with safety, fuel may be jettisoned above 7000
feet agl in winter and above 4000 feet agl in summer. For fuel to be jettisoned below these
levels the situation must be unavoidable.
13.4 A vertical separation of at least 1000 feet between aircraft should be maintained.
13.5 Adjacent ATC units and control sectors should be informed of the fuel dumping taking
place, including co-ordination with units providing services outside controlled airspace
where the aircraft’s track is near to the boundary of controlled airspace (both laterally and
vertically).
14.2 An overweight landing requires extra care on the part of the crew for the approach,
landing and deceleration on the runway. In particular, there are limits to the maximum
rates of descent on final approach that have to be achieved to ensure a successful
landing. Ideally, the aircraft should intercept the final approach track at or below the ILS
glide path to ensure that these rates of descent are not exceeded. Deceleration on the
runway may require additional braking with the attendant risk of wheel fires and it is likely
that the full length of the runway will be utilised. Except in the most extreme situations
where the aircraft is compelled to land at all costs, controllers should not observe
significant differences from normal aircraft performance with regard to rate of turn and
speed.
15. Facilitation
15.1 DfT require that, upon notification by a pilot of a suspected communicable disease,
controllers are to notify the appropriate authorities as detailed in MATS Part 2, the
Aerodrome Manual or local orders.
16.2 They are typically activated by use of a handle which deploys a solid fuel rocket out of a
hatch covering the compartment where the parachute is stored. Where the system has
been activated but has not deployed, the possibility exists that the rocket may still be live.
16.3 Deployment of the parachute assists a controlled descent rate, and in many situations the
pilot should be able to maintain radio contact subject to the level at which the parachute is
deployed and VHF coverage. The aircraft will generally drift with the wind and the pilot will
have no further control over the path of the aircraft. It should be noted therefore, that
deployment of the parachute does not guarantee survivability of an in- flight incident.
16.4 If time permits, a pilot deploying such a recovery system should notify this as part of
additional information within the normal emergency message, using the RT phraseology:
16.5 ATCOs should treat such pilot reports with the same priority as those pertaining to engine
failures and forced landings. Furthermore, they should ensure that RFFS are provided
with this information, as not only may it aid in identification of the aircraft but will reassure
them that if the chute has deployed, the system should present no further hazard.
16.6 Where it is known that a recovery system has been activated but has failed to operate,
ATCOs should also provide this information to RFFS, which should be alert for the
possibility of a live rocket on board the aircraft.
SECTION 5: CHAPTER 2
1. Introduction
1.1 For the purposes of this chapter, the terms strayed and unidentified aircraft have the
following meaning:
Strayed aircraft: An aircraft which has deviated significantly from its intended track, or
which reports that it is lost.
1.2 An aircraft may be considered, at the same time, as a “strayed aircraft” by one unit and as
an “unidentified aircraft” by another unit.
1.3 Controllers are reminded that a strayed or unidentified aircraft may be the subject of
unlawful interference and when this is suspected, shall follow the appropriate local
procedures.
1.4 The actions in response to strayed and unidentified aircraft detailed below may not be
exhaustive, as no two instances may be similar in nature. Furthermore, ANSPs should
ensure that their local instructions reflect any unit specific actions to be taken by
controllers when handling such aircraft.
2. Strayed Aircraft
2.1 When a controller becomes aware of an aircraft which has deviated significantly from its
intended track but has not reported as being lost, the following actions should be followed
in so far as is necessary:
(2) Inform other ATS units into whose area the aircraft has strayed or may stray
(SERA.11010(a)(1)(iii));
(3) Request appropriate assistance from D&D, other ATS units, and other aircraft in
establishing communication with the strayed aircraft (SERA.11010(a)(1)(iv) & (v));
(4) Notify, the Civil Watch Supervisor at the parent ACC in the event that unlawful
interference is suspected (SERA.11005 & SERA.11010(c)).
2.2 In the event that a pilot reports that he is lost, controllers should endeavour to provide
every possible assistance to the pilot and use all available means to determine the
aircraft’s position. Controllers should follow, in so far as is necessary, the actions outlined
below (SERA.11010(a)(1)(ii)):
(2) Use ATS surveillance systems and VDF in an attempt to locate the aircraft;
(3) If communications are poor, or the controller suspects that the aircraft is below
surveillance coverage, the pilot may be advised to climb. However, controllers
should be aware that such a climb may present a pilot with flight conditions beyond
their capabilities, and the pilot may prefer to remain with the surface in sight;
(4) Consider terrain clearance if the aircraft is flying at a low level. Controllers should
make allowance for terrain and obstructions within a wide area around the estimated
position of the aircraft and advise the pilot to climb if there is any doubt that
adequate clearance exists. If a pilot is unable or unwilling to climb he is to be
warned of potential terrain hazards in the area;
(5) Request assistance from other ATS units in determining the aircraft’s position.
(6) VDF bearings from other units may assist in fixing the position. If it is not possible to
establish the position of the aircraft immediately, bearings should be passed to the
pilot;
(8) Notify the Civil Watch Supervisor at the parent ACC in the event that unlawful
interference is suspected.
2.3 When the position of a lost aircraft has been established, the controller shall:
(1) advise the aircraft of its position and the corrective action to be taken. This advice
shall be immediately provided when the ATS unit is aware that there is a possibility
of interception or other hazard to the safety of the aircraft (SERA.11010(a)(3)(i));
and
(2) provide, as necessary, other air traffic service units and appropriate military units
with relevant information concerning the strayed aircraft and any advice given to that
aircraft (SERA.11010(a)(3)(ii)).
3. Unidentified Aircraft
3.1 When a controller becomes aware of an unidentified aircraft within airspace for which they
are the controlling authority and an ATC clearance is required, or when required by
appropriate military authorities, he should follow, in so far as is necessary, the following
actions:
(3) Inform D&D and any other affected ATS units or neighbouring FIRs, and request
their assistance in establishing the identity of and two- way communication with the
aircraft (SERA.11010(b)(2), (3) & (5));
(4) Notify, the Civil Watch Supervisor at the parent ACC in the event that unlawful
interference is suspected (SERA.11005 & SERA.11010(c));
(5) If possible, attempt to obtain information from other aircraft in the area
(SERA.11010(b)(4));
(6) As required, notify those units consulted in the tracing of the unidentified aircraft that
the aircraft’s identity has been ascertained;
SECTION 5: CHAPTER 3
Overdue Aircraft
1. Introduction
1.1 Overdue action should not be considered in isolation and the emergency actions
described in other chapters, in particular radio failure procedures should be applied if they
are appropriate. For example, if a radio equipped aircraft fails to make an expected report,
continued attempts should be made to re-establish communication while at the same time
commencing overdue action.
1.2 Overdue action is not related solely to the filing of a flight plan. If, at any stage of a flight
the pilot has made his intentions clear and subsequently does not arrive or report when
expected, controllers should seriously consider taking overdue action.
1.3 Overdue action described in this chapter must be commenced not later than the times
shown in the following paragraphs. The decision to take overdue action before these
times is left to the discretion of the controller. The following points may assist in making
the decision:
(1) Type of Aircraft: Strict adherence to the flight plan cannot always be expected of a
non-radio light aircraft.
(2) Route: Need for prompt action if the route is over sparsely populated areas,
mountainous country, long stretches of water, etc.
(3) Weather: The pilot of a non-radio aircraft might well be expected to extend his flight
time by deviating from his planned route to avoid bad weather. Where no additional
hazards exist, sufficient time for a deviation should be allowed.
2. Aerodrome Procedure
(3) Confirm ATD with aerodrome of departure using the quickest means of
communication;
(4) Inform the ACC supervisor of the situation and in co-ordination with him:
(c) Check with any likely aerodromes on and adjacent to the proposed route of the
aircraft.
(1) Notify the parent ACC that the aircraft is now fully overdue and state the action
already taken;
(2) In consultation with the ACC supervisor, continue endeavours to trace the aircraft,
e.g. notify local police or any other appropriate bodies to be on the lookout for the
aircraft if it is assumed that it has made a forced landing in a particular area.
(2) Request other aircraft flying in the vicinity of the aircraft’s last known position to be
on the lookout;
3. ACC Procedures
3.1 When aircraft are reported overdue, the ACC supervisor shall notify the D&D cell and take
the action described below according to the circumstances. The alerting message, which
is to be dispatched at the beginning of each phase of emergency, shall be telephoned to
the ARCC and confirmed by signal as described in Chapter 6.
(2) assist the destination aerodrome in checking with aerodromes on or in the vicinity of
the overdue aircraft’s proposed route;
(3) request other aircraft following the overdue aircraft’s proposed route to keep a
lookout for it having made a forced landing or crashed.
3B.2 Not later than 1 hour after the beginning of the Alert phase or when it is considered that
the fuel carried by the aircraft is exhausted, the ACC supervisor shall:
Table 1:
(1) Confirm ATD and time of last contact with preceding ATSU (if appropriate);
(2) Ask likely alternate aerodromes whether or not they have any information about the
aircraft;
(3) Where applicable, pass relevant information to the next ATSU on the aircraft’s route,
who will in turn pass information to succeeding units;
3C.3 Succeeding ATSUs along the proposed route of the aircraft shall follow the above action
by endeavouring to establish contact with the aircraft at the appropriate times and shall
warn units equipped with ATS surveillance systems to watch for the aircraft.
3D.2 Subsequently, the ARCC shall be notified that the Distress phase exists if no contact has
been made and either:
(1) 1 hour has elapsed beyond the last ETA for destination; or
(3) 1 hour has elapsed since the beginning of the Alert phase, whichever is the sooner.
(2) request other aircraft in the vicinity of the last known position of the missing aircraft
to look out for it; and
3E.2 If, after this action, the position of the aircraft is unknown or its fuel is considered to be
exhausted, notify the ARCC that the Distress phase exists and subsequently give all
possible assistance under their direction.
SECTION 5: CHAPTER 4
Radio Failure
1. Introduction
1.1 Radio failure procedures should not be considered in isolation and emergency action
described in other chapters should be applied if they are appropriate. For example, if an
aircraft fails to make a report when expected, overdue action may have to be taken at the
same time, particularly if the aircraft cannot be tracked on a situation display.
(1) an aircraft is observed to have selected A7600, and the pilot does not respond to
ATC communication;
(2) communication cannot be maintained with an aircraft on any flight which is being
provided with an ATC or advisory service;
1.3 The following procedures are based on the assumption that the pilot will comply with the
current procedures for radio failure detailed in the UK AIP.
1.4 Controllers should be alert to the possibility that a radio failure aircraft may have suffered
unlawful interference.
2.2 After attempts to establish normal two-way radio communication have failed, controllers
are to carry out the following standard radio failure procedures:
(1) Maintain separation between the radio failure aircraft and other known traffic;
(2) Give pertinent information about the movements of the radio failure aircraft to other
aircraft in the presumed vicinity;
(3) Ask aircraft in the presumed vicinity to establish communication with the radio failure
aircraft and relay messages;
Note: Pilots may attempt to contact ATC using HF or if equipped with approved installations for
accessing the UK telephone network may attempt to contact ATC via the D&D cell.
(a) level, route and EAT (or ETA) to which the radio failure aircraft is assumed to be
adhering; and
(b) the weather conditions at the destination aerodrome, a suitable alternate and, if
practicable, in areas suitable for a descent through cloud.
(7) When, in consultation with the operator, instructions to divert have been transmitted
to the radio failure aircraft, inform the alternate aerodrome and request that they
attempt to establish communication;
3A. PSR
3A.1 If an identified aircraft experiences a radio failure the controller shall instruct the aircraft to
make a turn(s). If movement of the Position Indication indicates that the aircraft receiver is
operating, the controller shall continue to pass instructions and resume normal service.
3A.2 If the Position Indication indicates that the aircraft is not repsonding to instructions(s), the
controller shall ensure that other known traffic are separated from the radio failure aircraft.
3A.3 If the position of the radio failure aircraft is not known the controller may continue to
provide a service to identified aircraft, provided the PSR cover is adequate and he is
confident that he can maintain 5 miles, or alternative approved minima within MATS Part 2
separation, from all unknown traffic.
3B. SSR
3B.1 If an aircraft carrying a secondary radar transponder experiences a radio failure the
controller shall instruct the pilot to make mode and/or code changes or to operate the
IDENT or SPI feature. If the responses indicate that the aircraft radio receiver is operating,
control of the radio failure aircraft may continue using the transponder replies as
acknowledgement of instructions.
3B.2 If the radio receiver is not working, pilots may be expected to select A7600 and follow
established procedures.
4.2 It should be noted that for many aerodromes in the UK, the radio communications failure
procedures published in the UK AIP AD 2 section differ from, or amplify, the basic
procedures published below.
4.3 For the purposes of these procedures, ATC will expect an IFR flight following the ATS
route structure to adopt the IMC procedure. If there is an overriding safety reason, the
pilot may adopt the VMC procedure.
4.4 Flights operating outside controlled or advisory airspace, without reference to ATS,
should only use these procedures when the pilot decides there is a need to alert ATC that
two-way radio communications failure has occurred.
4.5 It should be noted that the use of two-way communications failure procedures may result
in aircraft flying outside controlled airspace.
4.6 The procedures detailed in this chapter apply to two-way radio communications failure. In
the event that an additional emergency situation develops, ATC will expect the pilot to
select A7700.
4.7 The expression “Expected Approach Time” (EAT) will mean either an EAT given by the
appropriate ATC unit or, if the pilot has been given ‘No delay expected’, the ETA over the
appropriate designated facility serving the destination aerodrome.
4.8 Pilots are given an EAT of ‘Delay not determined’ when the destination runways cannot be
used for landing and it is not possible to accurately predict when they will become
available. In some circumstances an EAT of ‘Delay not determined’ will also be given
when a preceding flight has elected to remain over the holding facility pending an
improvement in weather conditions at the destination. If ‘Delay not determined’ has been
given, pilots should not attempt to land at the destination aerodrome, but instead divert to
the alternate destination specified in the current flight plan or another suitable aerodrome.
select SSR Mode A, Code 7600 with Mode C and land at the nearest suitable aerodrome.
Pilots should take account of visual landing aids and keep watch for instructions as may
be issued by visual signals from the ground. The pilot should report arrival to the
appropriate ATC unit as soon as possible. When VMC cannot be maintained, the pilot
should adopt the IMC Procedures as detailed below.
5.2 Subject to the provisions of paragraph 4.3 above, the pilot of an IFR flight experiencing
communication failure in VMC shall:
Pilots should take account of visual landing aids and keep watch for instructions as may
be issued by visual signals from the ground. The pilot should report arrival to the
appropriate ATC unit as soon as possible. If it does not appear feasible to continue the
flight VMC, or if it would be inappropriate to follow this procedure, the pilot should adopt
the procedures for flights in IMC detailed below.
Note: Pilots already in receipt of an ATC clearance may enter controlled airspace and follow the
procedures referred to above. Those flights that have not received an ATC clearance
should not enter controlled or advisory airspace unless an overriding safety reason
compels entry.
(b) if the failure occurs when the aircraft is following a notified departure procedure
such as a SID and clearance to climb, or re-routeing instructions have not been
given, the procedure should be flown in accordance with the published lateral
track and vertical profile, including any stepped climbs, until the last position, fix,
or waypoint, published for the procedure has been reached. Then for that part
of the 7 minutes that may remain, maintain current speed and last assigned
level or minimum safe altitude, if this is higher;
(c) thereafter, adjust the speed and level in accordance with the current flight plan
and continue the flight to the appropriate designated landing aid serving the
destination aerodrome. Attempt to transmit position reports and altitude/flight
level on the appropriate frequency when over routine reporting points;
(2)
(3)
(a) arrange the flight to arrive over the appropriate designated landing aid serving
the destination aerodrome as closely as possible to the ETA last acknowledged
by ATC. If no such ETA has been acknowledged, the pilot should use an ETA
derived from the last acknowledged position report and the flight-planned times
for the subsequent section of the flight;
(b) arrange the flight to arrive over the appropriate designated landing aid serving
the destination aerodrome at the highest notified Minimum Sector Altitude
taking account of en route terrain clearance requirements;
(c) if following a STAR, after the 7 minute period detailed above has been
completed, pilots should arrange descent as close as possible to the descent
planning profile. If no descent profile is published, pilots should arrange descent
to be at the minimum published level at the designated Initial Approach Fix;
(4) on reaching the appropriate designated landing aid serving the destination
aerodrome, begin further descent at the last acknowledged EAT. If no EAT has
been acknowledged, the descent should be started at the ETA calculated in
paragraph (4) (a) above, or as close as possible to this time. If necessary, remain
within the holding pattern until the minimum holding level, published for the facility,
has been reached. The rate of descent in holding patterns should not be less than
500 ft per minute. If ‘Delay not determined’ has been given, pilots are not to attempt
to land at the destination aerodrome, but instead divert to the alternate destination
specified in the current flight plan or another suitable aerodrome;
(5) carry out the notified instrument approach procedure as specified for the designated
navigational aid and, if possible, land within 30 minutes of the EAT or the calculated
ETA. When practical, pilots should take account of visual landing aids and keep
watch for instructions that may be issued by means of visual signals from the
ground;
(2) if it is believed that the radio communication transmitter is functioning, transmit blind
giving position reports and stating intentions;
(3) if, when radio communication failure occurs, the aircraft has not yet entered the CTR
concerned, the pilot must in all cases remain clear even if Special VFR clearance
has been obtained;
(4) if Special VFR clearance has been obtained and the aircraft has entered the CTR
concerned when the radio communication failure occurs, proceed as follows:
(a) aircraft inbound to an aerodrome within CTR – proceed in accordance with the
Special VFR clearance to the aerodrome and land as soon as possible. When
in the aerodrome traffic circuit watch for visual signals;
(b) aircraft transiting a CTR – continue flight not above the cleared altitude to leave
the CTR by the most direct route, taking into account weather limitations,
obstacle clearance and areas of known dense traffic.
Note 1: In a) and b), if flying on a heading advised by radar, when radio communication failure
occurs, resume own navigation and carry out the appropriate procedure described.
Note 2: In all cases, notify the ATC unit concerned as soon as possible after landing.
7.2 A controller who re-establishes communication with an aircraft must inform the unit at
which the radio failure procedure was initiated and provide it with information required for
further control of aircraft.
7A.2 If the aircraft lands without re-establishing radio communication the controller at the
aerodrome shall inform the unit at which the radio failure procedure was initiated.
7B.2 The lowest level in the stack and the level at which, according to published procedures,
radio failure aircraft are expected to leave the vicinity are to be kept clear for 30 minutes
after the time descent should have begun plus an appropriate period to allow the aircraft
to leave the vicinity.
SECTION 5: CHAPTER 5
1. Introduction
1.1 Instances may occur when civil and military aircraft operate unlawfully or without proper
authorisation within UK airspace, including:
(4) illegal use of an aircraft to effect the escape of prisoners or special hospital patients;
2. Safety
2.1 At all times the safety of the aircraft and its occupants is of prime importance. Unless
otherwise specifically directed by a responsible higher authority, the policy within UK
airspace is for Hijacked aircraft to land as soon as possible. Requests from the lawful
commander, which he states are essential for flight safety, are to be complied with and no
attempt shall be made to influence the course of events without his concurrence.
3. Direction
3.1 The Watch Supervisor at the parent ACC shall act as ATC Co-ordinating Authority for the
incident until, if required, responsibility is assumed by the UK Air Defence Authority under
standing procedures. Thereafter, the Watch Supervisor shall support the actions required
by the UK Air Defence Authority and co-ordinate actions with civil/military ATSUs as
agreed tactically.
3.2 Responsibility for overall direction of the incident will rest with Government officials acting
through the DfT or MoD and the ATC Co-ordinating Authority. Controllers should be aware
that their communications with these aircraft may be subject to Government instruction in
accordance with contingency plans not detailed here. Such contingency plans may result
in requests to issue instructions which, whilst not prejudicing safety in any way, controllers
would not otherwise consider suitable.
4. ATC Operations
4A. General
4A.1 When an occurrence of unlawful interference with an aircraft takes place or is suspected,
controllers shall attend promptly to requests by the aircraft.
4A.2 The aircraft concerned shall be given priority where possible and necessary action shall
be taken to expedite all phases of the flight, especially the safe landing of the aircraft. Any
reference to the special situation is to be avoided in air-ground communications with other
aircraft unless it has first been referred to in communications from the aircraft involved and
it is reasonable to assume that such reference will not aggravate the situation. Where
more than one aircraft is involved in the incident, reduced separation may be allowed
between the aircraft involved at the request of a lawful commander.
4A.3 An aircraft known or believed to be the subject of unlawful interference or which for other
reasons needs isolation from normal aerodrome activities shall be cleared to the
designated isolated parking position in accordance with local instructions. Where such an
isolated parking position has not been designated, or if the designated position is not
available, the aircraft shall be cleared to a position within the area or areas selected by
prior agreement with the Aerodrome Operator. The taxi clearance shall specify the taxi
route to be followed to the parking position. This route shall be selected with a view to
minimising any security risks to the public, other aircraft and installations at the
aerodrome.
4B.2 Whenever it has been established that the aircraft is transponding on A7500 the controller
shall attempt to verify by RTF with the aircraft concerned that the code selection is
intentional. The phraseology to be used is:
“(Callsign) confirm you are squawking assigned code (code assigned by ATC that it
would otherwise be squawking).”
4B.3 The RTF message must exclude specific mention of A7500. Whenever it has been
verified that the code has been intentionally selected, or when no verification can be
obtained, it shall be assumed that the aircraft has suffered unlawful interference.
4B.4 The phraseology above may also be used to provide a discrete check or prompt to pilots if
A7500 is not being displayed when information, such as is described in paragraph 6B
below, indicates a potential security threat. The pilot may then, if able, select A7500.
4C. Clearances
4C.1 Normal ATC clearances and provision of information pertinent to the safe conduct of the
flight shall continue to be transmitted unless otherwise directed by the appropriate higher
authority.
(1) “(Callsign) I am instructed by Her Majesty’s Government to refuse entry into United
Kingdom airspace. What are your intentions?”;
(2) “(Callsign) I am instructed by Her Majesty’s Government to inform you that landing
clearance has been refused for any airfield within the United Kingdom.”;
(3) “(Callsign) I am instructed by Her Majesty’s Government that you are to hold at (e.g.
exact reporting point, or latitude/longitude) at (level). Acknowledge.”.
4C.3 If an adjacent ATC agency is required to relay a message on behalf of the UK they should
be requested to pass the text verbatim.
4C.4 Nevertheless, the ATC unit is to make provision for normal separation should the aircraft
ignore the lack of clearance. The MoD, acting on advice from DfT, NATS or the Police,
may select a diversion destination if necessary.
5. Reporting Action
5.1 If the subject aircraft is within, or is planned to enter, UK airspace, or the interests of the
UK are in any way likely to be affected, the civil Watch Supervisor at the parent ACC must
be informed immediately. It has been agreed that Hijack incidents and subsequent
relevant changes, occurring in European airspace, will be signalled by the affected State
to all other States. The reporting action to be taken by ATC units is detailed in Section 6.
(2) Refusal or inability to comply with ATC instructions (including vectoring) with no
good reason;
(3) Loss of RTF contact, particularly associated with flight profile deviation;
(5) Use of non-standard phaseology by the crew, or other covert attempt to highlight the
situation (marked change in voice characteristics, etc.);
(6) Selection of A7600 (RTF failure) or A7700 (emergency), particularly associated with
flight profile deviation;
6B.2 In the case of the latter three bullet points, these would normally mean that the identity of
the aircraft is unknown until other factors become apparent. Individual events may not
constitute suspicious aircraft/pilot activity alone, however a combination of such events
should be considered as an unusual occurrence and the appropriate alerting action
undertaken.
SECTION 5: CHAPTER 6
Alerting Service
1. Introduction
1.1 Alerting service shall be provided by air traffic service units in accordance with (EU)
923/2012 SERA.10001:
Note: For the purposes of SERA.10001(a)(1), the United Kingdom also provides an Alerting
Service to all aircraft receiving an Air Traffic Service (ATS).
(2) in so far as practicable, to all other aircraft having filed a flight plan or otherwise
known to the air traffic service unit; and
1.2 The responsibility for initiating action normally rests with the ATSU that was last in
communication with the aircraft in need of search and rescue aid or that receives the
news from an outside source.
2. Aerodromes
2.1 Approach and aerodrome control units, when they are aware that an aircraft is in need of
search and rescue aid, shall immediately:
(1) set in motion the local rescue services and emergency organisations, as described
in Chapter 7; and/or
(2) notify by telephone the Watch Supervisor at the parent ACC. The contents of the
telephone message are shown in paragraph 9 below.
3.2 If the position of the aircraft is in doubt, emergency action shall be initiated by the ACC
responsible for the FIR:
(1) within which the aircraft was flying at the time of the last communication;
(2) that the aircraft was about to enter when communication was last established at or
close to the boundary;
(3) within which the destination aerodrome is located, for aircraft which are either:
3.3 The ACC shall take emergency action, with the agreement of the ATSU concerned, when
an aircraft crashes during the transfer of control from one unit to another.
(1) Confirm notification to the ARCC by signal using the prefix INCERFA, ALERFA, or
DETRESFA;
(2) Ensure that a supplementary flight plan is requested from the departure aerodrome;
(3) Inform the original destination aerodrome of a crash and of the action taken;
(4) If it is known that an aircraft which has crashed or is likely to crash has a dangerous
cargo on board, inform the rescue services;
(6) If the incident is reported by an outside source, take the name, address and
telephone number of the person reporting it.
5.2 The ACC shall notify aircraft emergencies which require search and rescue aid to the
ARCC as detailed in paragraph 3 above. Other ACCs, which may be involved, shall also
be informed. Details of the telephone message appear in paragraph 9 below.
5.3 The ARCC controller is responsible for initiating search and rescue action. To assist him
in this task, the Watch Supervisor may include a recommendation for search and rescue
action in the telephone message.
5.4 Messages shall not be delayed because of lack of information. If a message is incomplete
a further message is to be sent when the information is available.
(1) if any useful additional or significant information is received, e.g. information relating
to any dangerous goods carried by the aircraft; and
5.6 If an alerting message is received from an adjacent ACC, the Watch Supervisor shall:
(1) telephone the message to the ARCC without delay and confirm by teleprinter signal
(unless it is known that the ARCC has the information);
(2) assist the initiating ACC in searching for information about the emergency aircraft.
6.2 When aircraft in the service of the Coastguard are being used for search and rescue
purposes they will adopt the callsign “Coastguard Rescue”.
7. Phases of Emergency
7.1 The table below shows the phases into which emergencies fall. The decision to declare a
phase earlier than described must be left to the discretion of the controller.
8. Telephone Precedence
8.1 Most ATC units have direct operational telephone lines for use in emergencies.
(1) DISTRESS;
8.3 A DISTRESS call is used for a call of extreme operational emergency or concerned with
the safety of human life. It takes absolute precedence over all other calls and will be
connected immediately. Subject to telephone equipment capability, other calls will be
disconnected if necessary. On NATS networks the term “DISTRESS CALL” is used with
the routeing instruction, e.g. “Distress call to Scottish AC”.
8.4 An URGENT precedence is used for operational and administrative calls which should not
suffer the delays of ordinary calls. However, connected ordinary calls will only be
disconnected, subject to equipment capability, at the request of the caller. Staff at civil
aerodromes and civil ATSUs are to use the term CIVIL URGENT for such calls. Military
units and government departments use the term GOVERNMENT URGENT.
8.5 DISTRESS and URGENT calls should be kept to a minimum consistent with safety and a
controller should be prepared to give his name to the operator.
9. Telephone Message
9.1 The alerting message by telephone shall comprise the following information overleaf:
Unit which made the last contact, time and RTF frequency Last reported position and
method of determination Aircraft colour and markings
Dangerous goods carried as cargo
Action taken by reporting unit
Other pertinent information (To include recommendation for SAR action if appropriate)
10.2 Within Europe the use of the operations procedure is applicable to all sectors of flights
over mountainous or sparsely populated areas, including sea areas (Doc 7030). However,
the use of this procedure in other scenarios is permitted in accordance with MATS Part 2.
10.3 Controllers who do not receive an “operations normal” report when expected should
attempt to contact the pilot using the following phrase:
10.4 Following the pilot’s failure to respond to three successive attempts to confirm operations
normal, controllers should initiate overdue action.
SECTION 5: CHAPTER 7
1. Introduction
1.1 The responsibility for alerting the aerodrome emergency services normally rests with the
air traffic service. In general, the ATSU last in communication with the aircraft, or which
receives information from an outside source that an aircraft is in need of rescue aid, shall
initiate action.
1.2 No specific instructions can be made for an aircraft that crashes during the transfer of
communication from one ATSU to another, but as soon as either unit becomes aware of
the incident it must be agreed immediately which unit is to alert the emergency services.
2. Aerodrome Operator
2.1 The Aerodrome Operator is responsible for:
(2) determining the radius of action of the Aerodrome Fire Service, which may include
an area adjacent to and outside the boundary. The size of attendance within this
radius will as far as is possible be predetermined and detailed in MATS Part 2;
(3) advising ATC and Aircraft Operators whenever the fire and rescue services are
depleted for any reason. Such messages will normally be given in a form which is
suitable for immediate relay to aircraft.
3.1 If the rescue services are depleted for any reason the ATC unit at the aerodrome shall:
(1) transmit to aircraft the message received from the Aerodrome Operator. An example
of the phraseology is shown in CAP 413;
3.2 The table below shows the rescue and fire fighting categories according to the overall
length and width of the largest aircraft normally using the aerodrome over a given 12-
month period.
Table 1:
3.3 Category 1 and 2 aerodromes may apply remission on one category higher than their
promulgated category. A Category 1 aerodrome may accept a Category 2 aircraft
provided that during the busiest three months of the preceding twelve months, there were
less than 700 movements of those aircraft. Similarly Category 2 aerodromes may accept
Category 3 aircraft under the same conditions. Remission is only applicable for these two
given situations.
3.4 When full emergency or local standby action is to be instituted the pilot should be asked to
confirm the aircraft type unless there is a reasonable assurance from another source that
the type shown in the flight plan is correct.
3.5 Whenever possible controllers should anticipate the need for Aerodrome Fire Service
vehicles to cross runways and should issue clearances in advance of requirements. Other
traffic may be stopped or diverted to avoid conflict with appliances.
3.6 If it is known that an aircraft which has crashed or is about to crash had radioactive
material on board or is carrying any dangerous goods, including agricultural chemicals in
a crop spraying aircraft, the rescue services shall be so informed.
3.7 In the event of an aircraft on the ground reporting that it may be on fire or when an aircraft
on the ground is advised of signs of fire, the surface wind shall be passed to the aircraft
with the acknowledgement of the pilot’s report or together with the transmitted
observation.
aerodrome boundary. Normally a full attendance is made to all incidents within the
boundary.
5.2 The following terms are in general use but individual variations and additional terms may
be found in local emergency orders.
(2) outside the aerodrome boundary (other than aircraft accidents) which is liable to
constitute a danger to flying or aerodrome property;
(3) which the Aerodrome Rescue and Fire Fighting Service might attend where the
response is according to an agreement with the local emergency services;
(4) which is in response to calls from the public or police on humanitarian grounds.
6.2 Communication will only take place when the aircraft is on the ground and the pilot will
maintain a listening watch on the appropriate ATC frequency. The ATC unit will be
informed when 121.6 MHz is to be used.
6.3 Controllers should be aware that, if called upon to facilitate communications between a
pilot and the Aerodrome Fire Service on 121.6 MHz, the company callsign of the aircraft
may not be readily apparent to the Aerodrome Fire Service who may attempt to
communicate using the aircraft’s registration as displayed on the fuselage.
7A.2 Operator may wish to take action in accordance with the Civil Aviation (Investigation of
Accidents) Regulations 1996, which provide that an aircraft may be removed or interfered
with so far as may be necessary for the purpose of preventing any danger or obstruction
to the public or to air navigation.
8.2 The level of protection to be provided at a heliport is determined according to the overall
length, including the tail boom and rotors, of the longest helicopter irrespective of its
frequency of operations. However, during anticipated periods of operations by smaller
helicopters, the heliport fire fighting category may be reduced to that of the highest
category of helicopter planned to use the heliport at that time.
Table 1:
SECTION 5: CHAPTER 8
Miscellaneous Procedures
2. Ships in Distress
2.1 Occasionally, when the SAR organisation is attempting to give aid to a ship in distress
whose precise position is uncertain, the RCC may request an ACC to ask aircraft
operating or about to operate in the vicinity of the ship to report if they see any sign of it
along or near their normal route.
2.2 The ACC shall notify all aircraft in communication with them and which are in the vicinity
of the search area. The ACC shall also pass on the request to all civil aerodromes likely to
have aircraft in the area.
2.3 If an aircraft reports a sighting direcly to the ACC, the RCC that made the original request
shall be informed without delay.
2.4 If a sighting is reported to an ATSU other than an ACC, the unit shall advise its parent
ACC who in turn shall advise the RCC.
2.5 When a sighting is reported, ATC shall ask the reporting aircraft to attempt to guide other
ships to the scene.
2.6 The RCC will inform the ACC as soon as searching by aircraft is no longer required and
the ACC shall relay this message to all units which had been asked to assist in the
search.
3.2 The CAA Expert Team should be activated through the CAA AR:
AR normal operating hours – Principle Airspace Regulator (Tel: 0207 453 6586 or Email:
ausops@caa.co.uk)
Outside of AR normal operating hours – The Duty Airspace Regulator (Tel: 07798
571385) and on the basis of information received from one of the following sources:
(5) Internal;
(6) Any other reliable source of information, such as the Department for Transport, the
Ministry of Defence and the Department of Trade and Industry.
3.3 In the event of an incident, one or more of the above will contact AR, who will alert
members of the CAA Expert Team. Initially, ACCs are to provide tactical re-routeing of
aircraft in, or adjacent to, the UK FIR as necessary. The CAA Expert Team will advise
subsequent action.
3.4 Contact numbers for the CAA Expert Team are held by the CAA AR. AR Operations can
be contacted on 0207 453 6599 or ausops@caa.co.uk.
SECTION 5: CHAPTER 9
1. Introduction
1.1 A bomb warning involving an aircraft is to be treated as an emergency and controllers are
to follow the procedures and general guidance given in Chapter 1 of this Section.
Controllers shall not provide any advice or suggestions concerning action to be taken by
the flight crew in relation to an explosive device.
1.3 Operators wishing to pass warning messages to their pilots have been advised to contact
the Watch Supervisor at the appropriate ACC.
2. Assessment of Warnings
2.1 Bomb warnings are usually anonymous and are communicated by telephone or in writing
and normally identify a specific aircraft in flight. Each bomb warning should where
possible be assessed to determine its credibility and the level of risk. ATC, whilst having
responsibility for flight safety, has a much more limited responsibility in threat cases. ATC
is a vital communication and support facility but should not take part in the threat
assessment. Aerodrome Authorities and Airline Operators whose assets are involved take
the lead in assessing the threat and have specialist assessors for that purpose. The pilot
may or may not be involved in that analysis but the assessors are recommended to
consult with the DfT and the police as necessary. Appropriate and timely notification is
vital. Threat assessors categorise bomb warnings as follows:
Category RED
A credible threat relating to a specific target, or where the caller has positively identified
himself or the organisation involved, likely to involve danger to people, property and/or
operational/commercial activities and therefore requires immediate protective measures
e.g. diversion of an aircraft in flight.
Category AMBER
Category GREEN
3. Procedures
3A. General
3A.1 Bomb warnings involving aircraft in flight that are Cateogry Red, or where there has been
no time to categorise the threat, are to be treated as an emergency and provided with
flight priority A.
3A.2 Flights that are categorised as Category Amber may be treated as an emergency
depending on the response determined by the ‘NatRep’ (National Representative of the
Air Defence Authority). Such flights are to be allocated flight priority category A and
assistance requested by the NatRep and/or the pilot is to be given to enable the aircraft to
land as soon as possible. Controllers are to follow the procedures and general guidance
for Aircraft Emergencies in Chapter 1.
3A.3 When the captain of an aircraft becomes aware of a bomb threat and has sufficient
concern, he will declare an emergency using the RTF phraseology “MAYDAY, MAYDAY,
MAYDAY” and will describe the nature of the emergency as “Bomb On-board”. The
captain will likely request a landing at the nearest suitable aerodrome.
3A.4 The NatRep is responsible for deciding which airport the aircraft will land at and the route
they will take to get there, including whether or not the aircraft overflies densely populated
areas. This decision will be based on advice provided from both DfT and NATS.
3A.5 Aircraft Operators have been advised that aircraft subject to a bomb threat where a
response e.g. a diversion and/or expedited landing is deemed necessary should, unless
already committed, avoid over-flying densely populated areas and land at the nearest
adequate or suitable airport.
Table 1:
Situation Action
(1) Inform aircraft operator or company representative. If the warning
is received from ATSU check whether:
Trace aircraft and pass the message to pilot by the quickest means
available.
If Operator requests
that pilot is passed Messages passed to another ATSU by telephone must be confirmed by
warning message. signal, priority SS, identifying the subject aircraft.
3C. Aerodromes
3C.1 When a bomb warning is received at an aerodrome ATSU the senior controller is to
ensure that the appropriate local emergency orders are carried out.
3C.2 If the aircraft is in flight the senior controller shall, in addition, ensure that the Watch
Supervisor at the parent ACC is informed. Messages to pilots from operators must always
be referred to and co-ordinated with the appropriate ACC Watch Supervisor.
3C.3 If the aircraft is likely to land at the aerodrome, although it may not be in contact with the
unit, the local emergency orders are, nevertheless, to be carried out.
3C.4 An aircraft on the ground should be advised to remain as far away from other aircraft and
installations as possible and, if appropriate, to vacate the runway. The aircraft should be
instructed to taxi to a designated or isolated parking area in accordance with local
instructions. Should the flight crew disembark passengers and crew immediately, other
aircraft, vehicles and personnel should be kept at a safe distance from the threatened
aircraft.
3C.5 An aircraft known or believed to be the subject of unlawful interference or which for other
reasons needs isolation from normal aerodrome activities shall be cleared to the
designated isolated parking position in accordance with local instructions. Where such an
isolated parking position has not been designated, or if the designated position is not
available, the aircraft shall be cleared to a position within the area or areas selected by
prior agreement with the Aerodrome Operator. The taxi clearance shall specify the taxi
route to be followed to the parking position. This route shall be selected with a view to
minimising any security risks to the public, other aircraft and installations at the
aerodrome.
4. Reporting
4.1 Reporting action is to be in accordance with Section 6.
SECTION 6: CHAPTER 1
General Guidance
1. Introduction
1.1 The immediate action that must be taken by a controller at an operational position when
an AIRPROX is reported, is described in Section 1. The purpose of this section is to list,
for quick reference, the subsequent reporting action for accidents, incidents, alleged
breaches of legislation or AIRPROX events. It contains detailed instructions common to all
ATSUs. Instructions amplifying these procedures or peculiar to a unit will be found in
MATS Part 2 or local unit instructions.
1.2 To ensure prompt follow up action, all available information should be forwarded to the
relevant authority following an incident. In particular, when a controller has a subsequent
conversation with the pilot concerned, details of this exchange should be included as part
of the reporting procedure. These should include items such as:
(3) whether or not the controller considers the matter closed from a flight safety
viewpoint.
1.3 It is accepted that these supplementary details may well be dispatched after the initial
reporting documentation. ANSPs should have appropriate procedures for ensuring that all
details are correctly forwarded to the relevant bodies.
1.4 When a possible infringement of legislation is involved, controllers should follow the
guidance contained in Chapter 4.
1.5 Common telephone numbers and postal addresses used in reporting action are listed in
Appendix H.
1.6 Units may find it useful to make copies of Appendix H, or any other part of this section, for
display at suitable positions in control rooms.
1.7 ANSPs that have an ECCAIRS/ADREP complaint format, containing the appropriate
mandatory data fields, may submit an MOR via this format. Other ANSPs who do not
operate a system capable of producing a compliant format are to use the EU Reporting
Portal for MOR submissions.
2. Reports by Telephone
2.1 Some occurrences require a report to be made fairly promptly by telephone, e.g. malicious
interference to VHF communications. Telephone numbers appear in the directory located
in Appendix H.
3. Reports
3.1 All reports required from individual controllers about incidents and accidents are to be
reported to their organisation (their ANSP employer), in line with MATS Part 2 or local unit
instructions. The organisation is to collect all reports and other related documents and
send them to the appropriate address. Submission of a completed reporting, provided it
contains all information required by law, constitutes compliance with Reg. (EU) 376/2014.
The required information is set out in this Regulation. Further guidance is found in CAP
382, available from the CAA website.
(1) Amplify the facts with explanations but do not attempt to pre-judge or investigate;
(2) Refer to the watch log, flight progress strips (FPS) or any other document for
accurate details of times, dates, places, aircraft registration, etc;
(3) Use accepted aeronautical abbreviations (except for CA939 – Alleged Infringement
of Legislation);
(7) If you have not heard the RTF recording endorse your report ‘The events described
have not been checked for accuracy against the appropriate RTF recording’.
4. ATS Records
4.1 All ATS records concerning unusual occurrences must be preserved until enquiries or
investigations have been completed. In particular:
(3) the original FPS are to be retained at the unit, or in the case of electronic strips,
appropriate records secured.
5A. Accidents
5A.1 Replay of original RTF recordings and access to original communications logs and the
contents of FPS record stores is normally permitted only on the authority of the AAIB.
These facilities will be made available to ATC if immediately essential to the safety of the
subject aircraft or any others (e.g. to help establish the position of the aircraft involved to
facilitate search and rescue). If the authority of the AAIB cannot be obtained in time, the
authority of the senior controller available shall be accepted. Written confirmation of this
authority may be required.
5B.2 Occasions may arise when replays of RTF recordings are requested in circumstances not
associated with accidents, incidents or AIRPROX. Such requests may originate from ATC
or from outside organisations (e.g. airline representatives) but, in all such cases, the
written authority of the responsible person will be required to release the information.
6. Disclosure of Information
6.1 The contents of reports described in this section are to be suitably protected in
accordance with Reg. (EU) 376/2014 Article 15. If there is any doubt about the identity of
an individual requesting report details, a controller should ask for the telephone number,
check that it is authentic and return the call.
6.2 Members of the press and general public who make enquiries about an occurrence should
be referred to the person authorised to release information. Reg. (EU) 376/2014 and its
Guidance Material offers guidance on the release of information. Additional instructions on
relations with the press and general public may appear in MATS Part 2 or local unit
instructions.
6.3 Controllers should not approach a pilot or the Aircraft Operator if there is an alleged
infringement of legislation. Guidance for the occasions when the pilot contacts ATC is
given in Chapter 4.
6.4 Controllers may contact the Aircraft Operator by telephone to obtain details for other
reports but they are neither to discuss the occurrence further nor offer opinions as to
cause or responsibility. If aircraft operators require further information they are to be told
from which authority they will, in due course, hear. These are:
(3) for AIRPROX and incidents – CAA (Safety and Airspace Regulation Group) or
United Kingdom Airprox Board (UKAB).
SECTION 6: CHAPTER 2
1.2 The assessment procedure, following the reporting action at an aerodrome or ACC
described in this section, falls into two phases:
1A.2 The Principal Inspector will decide whether or not to provisionally vary the controller’s unit
endorsement, rating or licence, if appropriate and the extent, if any, of further remedial
action, e.g. competence check, period of training etc. and advise the nominated unit
manager accordingly. The act of withdrawing the controller from duty pending the
conclusion of this work is likely to be sufficient to address any immediate safety concerns
and will provide time for further assessments to be made where the controller’s
competence is in doubt, ATC procedures are suspected of being unsafe or the equipment
might be at fault.
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(1) enable immediate action to be taken locally to prevent a recurrence, e.g. cease
using a particular procedure, withdraw suspect equipment etc;
(2) include evidence which will form the basis of the in-depth investigation of the
incident. It is to be discussed with the appropriate Principal ATS Inspector at the
earliest opportunity. Internal procedures ensure that relevant incident material is
transferred between CAA departments as required.
1A.4 Whether or not the Principal ATS Inspector requires a local assessment, the unit manager
should carry out a local assessment for the purposes of 1A.3(1) above.
1A.5 The Unit Manager should ensure that any local unit investigation is conducted in
accordance with local unit procedures.
1B.2 ATSI will analyse the evidence and seek to identify the causes of the occurrence in their
report conclusion. Where appropriate, recommendations can be made.
1B.3 The subsequent report from the ATS Investigator is submitted to the appropriate Principal
ATS Inspector.
1C.2 Whether or not ATC is implicated in the cause of the incident, reports are submitted as
MORs to the CAA and in the case of an accident also to the AAIB. The diagram on the
following page illustrates the routeing for an AIRPROX report. Provided AIRPROX is
clearly mentioned or annotated on the original MOR then the report is forwarded to UKAB
by SDD.
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AIRPROX
Pilot
Air Traffic Service Unit
Pilots of EASA Annex 1
Aircraft: Completes MOR
1- File MOR (Annotate Occurrence as an
annotated as an AIRPROX.
AIRPROX);
2- Provides copy of filed report to ATSU
Pilots of EASA Annex 2
Manager; and
Aircraft: Completes CA1094A
3- Controller retains copy of filed report.
or may file an MOR annotated
as an AIRPROX.
Manager Air Traffic Services
or Unit Manager
Note: This flow diagram should be read in conjunction with the reporting action for aerodromes
and ACCs detailed in this section.
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2. Controller Overload
2.1 Controllers who consider that they were involved in an ATC situation during which they
experienced excessive workload to the point where the safety of aircraft under their
control was, or could have been, compromised, shall file an MOR. When completing the
report, controllers shall commence the narrative with ‘Overload Report’. The Unit
Manager shall ensure that a unit investigation is carried out into the alleged overload and
shall submit a follow up in line with EU376/2014 timelines.
2.2 The Unit Manager shall include in the report the effect the overload had on the controller’s
ability to safely handle aircraft under his control and, if appropriate, details of the remedial
action the unit has decided to take.
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SECTION 6: CHAPTER 3
1. Explanation of Terms
1.1 Reg. (EU) 376/2014 (article 4 (5)) requires that a list classifying the type of occurrences
that require report action is created. This list is detailed within Reg. (EU) 2015/1018,
which is not reproduced within this document. However, the following information gives
guidance on the types of occurrence and the action to follow at unit level. It is also
recognised that some units may have additional reporting action as detailed in local unit
instructions.
1.2 In this section the term ‘incident’ means any of the unusual occurrences, involving aircraft,
which are tabulated below.
Table 1:
Incident Explanation
An aircraft, manned or unmanned, receives substantial damage or causes
Aircraft Accident
death or serious injury or damage to property.
An occurrence associated with the operation of an aircraft which, in the case of
a manned aircraft, takes place between the time any person boards an aircraft
with the intention of flight until such time as all such persons have disembarked,
or in the case of an unmanned aircraft, takes place between the time the aircraft
is ready to move with the purpose of flight until such time as it comes to rest at
the end of the flight and the primary propulsion system is shut down, in which:
(1) a person is fatally or seriously injured as a result of:
(a) being in the aircraft, or
(b) direct contact with any part of the aircraft, including parts which have
become detached from the aircraft, or
Reportable
Accident (c) direct exposure to jet blast,
except when the injuries are from natural causes, self-inflicted or inflicted by
other persons, or when the injuries are to stowaways hiding outside the areas
normally available to the passengers and crew; or
(2) the aircraft sustains damage or structural failure which adversely affects
the structural strength, performance or flight characteristics of the aircraft,
and would normally require major repair or replacement of the affected
component, except for engine failure or damage, when the damage is
limited to a single engine, (including its cowlings or accessories), to
propellers, wing tips, antennas, probes, vanes, tyres, brakes, wheels,
fairings, panels, landing gear doors, windscreens, the aircraft skin (such
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Incident Explanation
as small dents or puncture holes), or for minor damage to main rotor
blades, tail rotor blades, landing gear, and those resulting from hail or bird
strike (including holes in the radome); or
(3) the aircraft is missing or is completely inaccessible.
Serious Incident An occurrence involving circumstances indicating that an accident nearly
occurred.
A situation in which, in the opinion of the pilot or a controller, the distance
AIRPROX between aircraft as well as their relative positions and speeds have been such
that the safety of the aircraft involved was or may have been compromised.
Incident involving An occurrence which has endangered, or if not corrected would have
safety endangered an aircraft, its occupants or any other person.
Wildlife or An occurrence either witnessed by ATC or advised by a pilot where an aircraft
Birdstrike has come in to contact with one or more birds or other wildlife.
Incident on- A commander of an aircraft in flight, in pursuance of the powers bestowed on
board an aircraft him by the Tokyo Convention Act 1967, finds it necessary to restrain a person
in flight on board.
The unlawful seizure, or exercise of control, of an aircraft by use of force or
Hijacking
threats.
Unlawful use of Movement on the ground and flight of an aircraft by an unauthorised person or
aircraft for an illegal purpose.
Aircraft Ground An aircraft on the ground is in an emergency situation, other than an accident,
Incident and requires the attendance of the emergency services.
Unintentional An aircraft of 2300 kilogrammes or more all up weight touches down short of
use of unpaved the recognised landing area, overruns on landing or otherwise leaves the paved
areas surfaces of the manoeuvring area.
Aircraft Radio Radio faults including technical failure.
Equipment Fault
Radio Frequency Interruption of reception on ATC RTF frequencies by unwanted signals or
Interference atmospherics.
Ground Fault A report by an aircrew member alleging that a telecommunications facility is not
Report operating correctly.
2. Reporting Action
2.1 Reporting action will depend upon the circumstances of the incident. The actions to be
taken at aerodromes and ACCs are listed in the respective tables below.
If more than one circumstance applies to a particular incident then the actions applicable
to all appropriate circumstances must be taken.
E.g. an accident in the vicinity of an aerodrome is also one that is reportable. The
combined reporting action is to telephone the ACC and the Aerodrome Operator.
Subsequent action is to submit written reports from all concerned to SDD.
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Additional reporting action may be specified in MATS Part 2 or local unit instructions.
Note: Where the posts described in the tables below are not the job titles used locally, the
reporting action to be used shall be detailed in MATS Part 2 or local unit instructions.
Table 2:
Circumstances Reporting Action
Subsequent Action
of an Incident (by telephone to)
Aircraft Accident in the vicinity
ACC Watch Manager Submit an MOR
of the aerodrome
Aerodrome Operator (but see
additionally if an accident is
local emergency orders) ACC Submit an MOR
Reportable
can assist
Involves any of approach,
navigation or communications DEO at the aerodrome Submit an MOR
facilities
Unintentional use of unpaved
Aerodrome Operator Submit an MOR
areas
ACC Watch Manager
Aircraft Operator
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and
Incident on-board an aircraft Aerodrome Operator
in flight (aircraft intends to Submit CA939 to
land) Aircraft Operators Investigation and
Enforcement Team; if viewing
via PDF click here.
and
Alleged Infringement of
Legislation Submit CA 939 to
Investigation and
Enforcement Team; if viewing
via PDF click here.
See also Chapter 1 – GENERAL GUIDANCE and the flow diagram in Chapter 2
A LIST OF TELEPHONE NUMBERS AND LOCATIONS IS SHOWN IN THE DIRECTORY AT
APPENDIX H
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4.2 Reporting action is shown in the table below. Note that more than one circumstance may
be appropriate to an incident. Operational Supervisors should also ensure that actions
taken include those described in Section 5, Chapter 6, ‘Alerting Action’.
Table 3:
Circumstances of an
Reporting Action by telephone to Subsequent Action
Incident
Reportable Accident (if AAIB
reporting action not taken Submit an MOR
at an aerodrome) Civil Police
Serious Incident (this may
include some MAYDAY AAIB Submit an MOR
and PAN messages)
Aircraft Operators
AIRPROX Report Submit an MOR
Other ATSUs involved
Civil Police: Provide location of
AIRPROX as soon as practicable
to initiate tracing action
AIRPROX Report
ACC Ops Supervisor Submit an MOR
involving SUA
Aircraft Operator
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Circumstances of an
Reporting Action by telephone to Subsequent Action
Incident
May involve any of
approach, navigational or
System Control at the ACC Submit an MOR
communication facilities
at non-NATS aerodromes
DfT Duty Officer
Hijacking and unlawful
Submit an MOR
use of aircraft ACC Military Supervisor Next ATSU
concerned with the flight
Aircraft Operators (if action not
already taken at ATSU)
and
Alleged Infringement of
Legislation Submit CA939 to
Investigation and
Enforcement Team; if viewing
via PDF click here.
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See also Chapter 1 – GENERAL GUIDANCE and the flow diagram in Chapter 2
A LIST OF TELEPHONE NUMBERS AND LOCATIONS IS SHOWN IN THE DIRECTORY AT
APPENDIX H
5. Accident Reports
5A. Telephone
5A.1 When telephone action is required pass as much of the following information as is
available:
(7) Casualties;
(9) Lighting facilities, navigational and/or landing aids in use (as appropriate) and any
known unserviceabilities.
(2) Approach aids and Lighting facilities in use and their serviceability;
(3) Relevant information on the serviceability of the aerodrome facilities and surface;
6.2 The following list provides a number of typical examples of those incidents likely to be
considered serious. The list is not exhaustive and serves only as guidance to the
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definition of a serious incident. The AAIB are the final arbitrators in deciding whether the
incident will be considered serious. If doubt exists, an incident should be reported rather
than excluded:
(4) Take-offs from a closed or occupied runway with marginal clearance from
obstacle(s); Landings or attempted landings on a closed or occupied runway;
(5) Gross failures to achieve predicted performance during take-off or initial climb;
(6) Fires and smoke in the passenger compartment, in cargo compartments or engine
fires, even though such fires were extinguished by the use of extinguishing agents;
(7) Events requiring the emergency use of oxygen by the flight crew;
(12) System failures, weather phenomena, operations outside the approved flight
envelope or other occurrence which could have caused difficulties controlling the
aircraft; and
(13) Failure of more than one system in a reduced system mandatory for flight guidance
and navigation.
6.3 Where an AIRPROX is filed there is no need to follow the serious incident reporting
procedures as the details will be sent by the normal reporting systems to AAIB. Reporting
procedures shall commence as soon as practicable after the incident and, in all cases, no
later than 72 hours after the occurrence. It is accepted that all details may not be
available soon after the incident in which case the available information should be sent
within the required timescale and the additional details forwarded on as soon as possible
thereafter. If a serious incident occurs and ATC are not informed by the crew then the
onus rests with the flight crew to ensure that reporting action is taken.
6A. Telephone
6A.1 When telephone action is required pass as much of the following information as available:
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(7) Casualties;
(9) Where appropriate, lighting facilities, navigation and/or landing aids in use and any
known unserviceabilities.
7. AIRPROX Reports
7.1 AIRPROX reports are processed and handled by the UK AIRPROX Board (UKAB). ATSI
review all AIRPROX reports and may carry out a full investigation. During the ATSI
review the extent to which ATC were involved in the AIRPROX is assessed, and on
completion of any investigation, an appropriate report is forwarded to UKAB.
7.2 In order to comply with MOR procedures, the report from the originating ATSU shall
clearly state ‘AIRPROX’ and contain as much information as possible. SDD will then
forward the report to UKAB.
7.3 A pilot may file an AIRPROX report on the RTF or, after landing, by telephone or in
person. Following a pilot’s declaration that he will file an AIRPROX, controllers should
complete their own incident report. This should ensure that any action, such as recovery
of RTF or surveillance data can be initiated at the earliest opportunity.
7.4 Any completed AIRPROX reports, initiated by pilots, (including signals from foreign ACCs)
received at an ATC unit are to be sent without delay to the UKAB.
7.5 Controllers, when initiating the filing of an AIRPROX, shall file an MOR including clear
reference to the status as an AIRPROX. Pilots of aircraft involved in an AIRPROX
initiated by a controller should be informed by the controller or his unit management, as
soon as possible, that an AIRPROX is being submitted by ATC.
(1) If the unidentified aircraft is suspected to be military (of any nationality) or not
positively identified as civil, telephone LACC (Mil) Radar Analysis Cell (RAC) and
request search;
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(2) If the search for a civil aircraft (especially light aircraft outside controlled airspace) is
unsuccessful, telephone LACC(Mil) RAC and seek assistance. In particular, ask if
any military unit has any knowledge of the reported civil aircraft.
7A.2 In both cases confirm the request by including LACC(Mil) RAC in the list of addresses of
the signal.
7A.3 Where ACC trace action is taken entirely by LACC(Mil) RAC, final signal action will be
taken by LACC(Mil) RAC.
7A.4 If a military aircraft, not in communication with a civil ATC unit, reports an AIRPROX with a
civil aircraft the ACC will be requested by LACC (Mil) RAC to attempt to trace the reported
aircraft.
7A.5 LATCC (Mil) RAC is responsible for all trace action undertaken at the London AC and
LTCC and the Prestwick AC.
8.2 The holder of an Air Traffic Controller’s licence or Flight Information Service Officer’s
licence is to report, within 72 hours, any occurrence which has, or if not corrected would
have, endangered an aircraft, its occupants or any other person. The CAA Website
contains guidance on what is a reportable occurrence but ultimately the individual licence
holder involved will have to use his own judgement. Reg. (EU) 2015/1018 contains details.
8.3 To enable other reports to be completed without delay licence holders should, if possible,
inform operators and other ATS units involved as soon as practicable.
8.4 If telecommunications services and facilities are involved, the systems controller or the
DEO should be advised of the circumstances of the occurrence without delay.
8.5 Licence holders are to report all occurrences regardless of the category or nationality of
the aircraft.
8A.2 Occurrence Reports are treated confidentially to maintain full and free reporting from the
aviation community and to protect the identity of the individual in accordance with EU
legislation.
8A.3 If the controller considers that the incident he is reporting under the MOR scheme may
have involved a breach of legislation he is advised to seek the views of local
management. If after consultation it is decided that CA939 action is appropriate a
completed form CA939 should be sent to the Investigation and Enforcement Team (IET)
accompanied by a MOR which indicates that CA939 action has been requested.
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8A.4 If a reporter encounters a situation where a mandatory report is not appropriate but has an
allegation about an individual or organisation that may affect safety, then a Voluntary
Occurrence Report (VOR), or a Whistleblower report may be filed. Details of the
whistleblowing process can be found on the CAA website via the MOR scheme page; if
viewing via PDF click here.
(3) The name and nationality of the person under restraint and the details of his journey;
(4) A description of the incident in which the person was involved and the position of the
aircraft at the time;
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SECTION 6: CHAPTER 4
Infringement of Legislation
1. Introduction
1.1 Offences against the Civil Aviation Act, the ANO, its supporting Regulations or published
procedures may be one of three basic types:
(1) An offence against the Rules of the Air and ATC Regulations or against published
procedures;
(3) An offence against regulations having no direct bearing on safety (e.g. requirements
for registration and markings, carriage of documents or Customs requirements).
1.2 Offences in category 1.1(3) above should be reported by telephone to the nearest
representative of the appropriate authority (e.g. Customs) or, in cases of doubt, to the
CAA Investigation and Enforcement Team (IET).
1.3 Controllers should report offences in categories 1.1(1) and 1.1(2) above using form
CA939 in accordance with paragraph 3 below.
2. Tracing Action
2.1 If the offending aircraft has not been identified but is seen on a situation display, it is to be
tracked, if possible, until it appears to be landing. Correlation of the track and time with
the movements at the appropriate aerodrome should be attempted so that identification
can be made.
2.2 If the pilot’s name is volunteered it should be noted in the report. There is no requirement
to speak directly to the pilot concerned. However, if contact is made the pilot shall not be
invited or persuaded to give an explanation but if he does so voluntarily, it shall be written
down in his exact words and not paraphrased or interpreted. This does not constitute a
statement under caution but it does form a very important link in the chain of information
upon which to decide whether to prosecute. The reporting officer should endorse the form
with the date and time of completion.
2.3 If the pilot states that special circumstances existed, e.g. that service was being provided
by another ATSU, efforts should be made to corroborate the statement.
2.4 If the pilot asks what action is going to be taken, the controller should say that he is
endeavouring to trace the identity of an aircraft involved in an incident and that the
circumstances of the flight are being reported to the CAA for consideration of action to be
taken.
3. Written Reports
3.1 Alleged breaches of Air Navigation Legislation (ABANL) are to be reported on form
CA939. A link to this form is available on the CAA website under Aviation Industry
Related Issues via the ‘Make a report’ quick link; if viewing via PDF click here. Details
under the heading ‘General Information’ should be inserted if they are known. Copies of
statements and relevant supplementary evidence, such as watch log extracts and flight
plans, should be attached.
3.2 Staff having first-hand knowledge of the incident are to type their statements in a MOR
report. It should be noted that on this occasion code groups and aeronautical
abbreviations are not to be used.
4. Forwarding Reports
4.1 Reports on CA939 are to be sent to the CAA IET. Reports may be submitted by post or by
email as detailed on the form.
It is essential that any report which may merit prosecution is dealt with expeditiously. If
delays occur in the preparation of supporting documents, the CA939 is to be forwarded at
once and endorsed ‘additional documents to follow’.
4.2 Controllers are reminded that the event should be described with as much detail as
possible. The report should include the following where appropriate:
(1) The identification of all aircraft involved together with relative tracks and times
(3) A statement as to the degree of actual impact the event had on ATC operations
including any tactical avoiding or delaying action taken by ATC.
5. Military Aircraft
5.1 Although air navigation legislation does not normally apply to military aircraft (of any
nationality) all apparent contraventions are to be reported.
5.2 When an unidentified aircraft (suspected as being military) has apparently contravened
regulations, the LACC (Mil) RAC should be requested to take search action to establish its
identity. The reason for requesting the search must be clearly stated to distinguish it from
the search action following an AIRPROX report.
SECTION 6: CHAPTER 5
Miscellaneous Reports
1. Bird Strikes
1.1 Pilots are required to report all bird strikes (and other wildlife related events) in UK
airspace whether or not damage is caused. A controller receiving such a report should
obtain as much information as possible and complete an MOR clearly stating the nature of
the report.
2. Maritime Incidents
2B.2 ‘Oil Pollution Report’, or ‘... Pollution Report’ if a harmful substance other than oil is
suspected.
2B.3 A controller receiving a report should obtain as much information as possible to complete
a report in the format shown below:
A Date and time pollution observed and identity of aircraft reporting.
B Position and extent of pollution.
C Tide, windspeed and direction.
D Weather conditions and sea state.
E Characteristics of pollution.
F Name and nationality, or description, including any distinctive markings, of any
vessel seen discharging oil or other harmful substances; also assessment of course
and speed of vessel and whether any pollution observed ahead of the discharging
ship and the estimated length of pollution in her wake.
G The identity of any other vessels in the immediate vicinity.
H Whether or not photographs have been taken.
2C.2 Similar procedure should be followed if a pilot makes such a report by telephone after
landing.
3.2 Controllers are also reminded that a UFO report could require actions specified under the
‘unidentified aircraft’ requirements in Section 5, Chapter 2.
B Description of Object
Number of objects, size, shape, colours, brightness, any lighting configuration or
surface markings seen on the object, sound, smell, etc.
D How Observed
Naked eye, binoculars, other optical device, still or movie camera.
H Movements of Object
Changes in E, F and G may be of more use than estimates of course and speed.
K Nearby Objects
Telephone or high-voltage lines; reservoir, lake or dam; swamp or marsh; river; high
buildings, tall chimneys, steeples, spires, TV, radio or mobile phone masts; airfields,
generating plant; factories; pits or other sites with floodlights or other lighting; any
other aeroplanes or helicopters seen at the time.
L To Whom Reported
Police, military organisations, the press, etc.
O Other Witnesses
4. Sonic Boom
4.1 An ATSU receiving a report of a boom alleged to have been caused by an aircraft in
supersonic flight should obtain as much information as possible, including:
(3) Description of sound (e.g. single or double crack, dull boom or rumble, etc.);
4.2 The report should be passed immediately to the parent ACC, whose MATS Part 2 or local
unit instructions shall contain procedures for processing such reports.
(1) a change in the individuality of the transmissions, i.e. the controller’s voice
characteristics are not those previously experienced;
(2) the message transmitted is out of context with the expected next message; it is
obviously in error or uses incorrect phraseology;
(3) the messages are usually transmitted for a short time only and not repeated when
queried;
(4) the signal is sometimes received only by the pilot or controller, not both.
5.2 When illegal transmissions are suspected controllers should ensure that either the DEO or
ATC contacts the Radio Investigation Service. The Service is part of Ofcom and will seek
to track down the source of the transmissions and take appropriate legal action.
5.3 For this process to work, it is essential that the Radio Investigation Service is informed as
soon as practicable. They will require to know the content, character, type and location
where the transmissions were received. The 24-hour telephone number for the Service is:
01462 428528 and the associated fax number is: 01462 438885.
On weekdays, between 0900 and 1700, an alternative fax number is: 01462 428510.
5.4 It is important that the best possible evidence is made available for any potential
prosecution. Original tapes of communications received by the ground must be preserved
where possible. Advice from CAA Investigation and Enforcement Team (IET) can be
obtained if ANSPs are unclear on what action to take or what to preserve when cases
arise.
5.6 The ANSP’s MATS Part 2 or local unit instructions for categorising and reporting
interference based on the above guidance and that included in AIC 41/2006 (Pink 100)
and AIC 126/2006 (Pink 109).
SECTION 7: CHAPTER 1
Meteorological Services
1. Briefing of Controllers
1.1 Prior to taking-over watch, controllers shall obtain full information regarding the weather to
be expected during the period of their watch. This may be accomplished by a study of
forecasts and charts supplied routinely by the Met Office and, if clarification is necessary,
supplemented by a briefing from the designated forecast unit.
2. Explanation of Terms
2.1 The use of the words ‘cloud base’ in meteorological reports and aerodrome forecasts
means the height of the base of any cloud above aerodrome elevation.
2.2 The Meteorological Authority for civil aviation in the United Kingdom is the Civil Aviation
Authority, CAA House, 45–59 Kingsway, London WC2B 6TE.
3. Supply of Information
3A. Source
3A.1 Meteorological forecasting services to ATSUs are provided by the Met Office from the
Operations Centre at Exeter or other designated forecast offices, as directed by the
Meteorological Authority. As a general rule controllers shall only transmit to aircraft,
information that has been supplied, or agreed, by the Met Office. The exceptions are:
(1) Indicated wind direction and speed where anemometer indicators are fitted in the
control room;
(4) Information from an aircraft in flight may be passed to other aircraft when a
controller considers that it may be useful to them.
(5) Whenever this is done the controller shall state that the information originated from
an aircraft in flight and the time at which the observation was made.
3A.2 Controllers shall ensure a close watch is kept on the weather and report any sudden or
unexpected deteriorations or improvements observed, or obtained from pilots, to the duty
observer on the aerodrome or forecaster at the appropriate forecast office without delay.
Controllers may be asked to obtain weather observations from aircraft.
(4) thunderstorms with or without hail (that are obscured, embedded, widespread or in
squall lines) (TSGR or TS);
3B.2 Special and non-routine Air-Reports shall be recorded by ATS units using the model
AIREP SPECIAL form contained at Appendix J (SERA.12005(c)(1)) or similarly ANSP
produced document and the information disseminated, as soon as practicable in
accordance with (SERA.12020(a)) to:
(1) other aircraft concerned and shall cover the portion of the route up to one hour’s
flying time ahead of the aircraft;
(2) the Met Office at Exeter or Aberdeen (as appropriate), as soon as practicable, who
will decide whether the conditions warrant the issue of a SIGMET; and
Note: Other ATS units concerned are those that have flights under their jurisdiction which are
expected to enter the airspace concerned at a later stage of flight. Those flights could, for
instance, require rerouting before entering the airspace concerned. As an example, a
special air-report concerning volcanic ash or volcanic eruption could be necessary to
transmit to aircraft by ATS units in the FIR adjacent to that affected by the Air-Report.
(GM1 SERA.12020(a)(3))
3B.3 Transmissions to aircraft shall be repeated at a frequency and continued for a period of
time which shall be determined by the ATS unit concerned. (SERA.12020(b))
(2) Time;
3D.2 Special reports (see below) are to be identified as such on the aerodrome weather report
form or display. Similarly, elements of a routine report which show a specific change, and
which would otherwise require the issue of a special report, are to be underlined or
otherwise highlighted on the form or display.
Table 1:
Item
Direction in degrees True and speed in knots, usually averaged over 10
minutes. In addition, if appropriate to the same 10 minute period:
Surface Wind (1) Extremes in direction when the variation is 60 degrees or more but less
than 180 degrees and the mean speed exceeds 3 knots;
(2) Maximum wind speed when it exceeds the mean by 10 knots or more.
4.2 In reports to aircraft for take-off and landing, direction is to be expressed in degrees
Magnetic; and, where averaging is appropriate, the period shall be 2 minutes. In addition,
the extremes in direction and speed (gust and lull) during the past 10 minutes shall be
provided.
Table 2:
Item
Criteria to be agreed locally, based on changes of operational significance
at the aerodrome; otherwise:
(1) a change in mean direction of 60° or more, the mean speed
before or after the change being 10 kt or more, but a change
Surface Wind
of 30° when 20 kt or more;
(2) a change in mean speed of 10 kt or more;
(3) a change in gust speed of 10 kt or more, the mean speed
before or after the change being 15 kt or more.
(1) When the prevailing visibility changes from one of the following
ranges to another:
10 kilometres or more
5000 metres to 9 kilometres
3000 metres to 4900 metres
2000 metres to 2900 metres
1500 metres to 1900 metres
800 metres to 1400 metres 750 metres or less.
(2) When the minimum visibility in one or more directions becomes less
than 50% of the prevailing visibility, after being 50% or more of the
prevailing visibility, or when the minimum visibility in one or more
Surface Visibility
directions becomes greater than 50% of the prevailing visibility, after
being 50% or less than the prevailing visibility.
(3) If the minimum visibility is being reported, when the minimum
visibility changes from one of the ranges given in a) above, to
another.
Note: In addition, arrangements can be made at aerodromes where RVR
is not available, either permanently or during a temporary unserviceability,
to report a change from one range to another:
600 to 750 metres
350 to 550 metres
150 to 300 metres 125 metres or less
Item
At the onset, cessation or change in intensity of:
(1) Moderate or heavy precipitation (including showers):
(a) Freezing precipitation (of any intensity)
(b) Freezing fog
Weather
(c) Thunderstorm (with or without precipitation)
(d) Funnel cloud (tornado or waterspout)
(e) Squall
(f) Low drifting or blowing; snow, dust or sand.
Base: When the base of the lowest cloud covering more than half the sky
changes from one range to another:
2000 feet or more 1500 feet to 1900 feet
1000 feet to 1400 feet
700 feet to 900 feet
500 feet to 600 feet
Cloud 300 feet to 400 feet
200 feet
100 feet
Less than 100 feet (including sky obscured).
At certain aerodromes the upper limit may be higher.
Amount: When the amount of the lowest layer below 1500 feet changes
from half or less to more than half; and vice versa.
Pressure When the QNH or QFE changes by 1·0 Hectopascal or more.
Temperature When the air temperature changes by 2·0 degrees or more.
When an aircraft on the approach or on climb out reports severe icing
Severe icing and/or
and/or severe turbulence, and it is confirmed by the duty forecaster at the
turbulence local meteorological forecast office.
7. SIGMET
7.1 SIGMET messages are issued and disseminated on OPMET and AFTN when
phenomena which may affect the safety of aircraft have been reported, or are expected to
occur, in an area over which a meteorological watch is maintained.
7.2 The description of the phenomenon, its location, expected movements, expected
development and whether observed or forecast, is usually expressed in abbreviated plain
language using approved ICAO abbreviations. Only one weather phenomenon will be
referred to in each message. The messages are numbered sequentially from 0001 UTC
each day.
7.3 SIGMET messages are not usually valid for more than 4 hours (except volcanic ash cloud
where the period may be up to 12 hours) and are re- issued if they are to remain valid
after the original period expires. They can be amended when the conditions change and
cancelled as soon as the specified conditions cease.
7.4 The phenomena necessitating the issue of a SIGMET are listed below:
Severe turbulence
Note:* This refers not only to thunderstorms but also to cumulonimbus clouds that may not be
currently accompanied by a thunderstorm.
8. Forecasts
(2) Upper winds and temperatures – at 1000 ft, 3000 ft and 6000 ft;
(4) Weather conditions – surface visibility, weather and cloud (amount, type, height of
base and top);
(5) Weather warnings – strong winds and gales, turbulence, icing, mountain waves or
thunderstorms.
Additionally these forecasts are available in chart format as Form 214 (spot wind) and
Form 215 (low level weather).
8D.2 All TAFs are issued approximately one hour before the start of validity time. The update
periods of the TAF will be every 3 hours for aerodromes who are provided with 9 hour
TAF, and every 6 hours for aerodromes who are provided with 24 or 30 hour TAF.
8D.3 Additionally for selected aerodromes, landing forecasts (TRENDs) are added to each
routine METAR to indicate significant changes expected from the current weather
conditions over the next 2 hours.
9. Aerodrome Warnings
9A. General
9A.1 An ATSU may be provided with warnings of any of the following weather hazards which
could affect the safety of aircraft operations and parked aircraft: gales, squalls, snow,
frost, thunderstorm, freezing precipitation and fog.
9A.2 Once the service has been approved by the Meteorological Authority, the procedure for
the issue of warnings is arranged locally between the aerodrome management and the
designated liaising meteorological forecast unit and is reviewed annually.
9A.3 A warning usually remains in force until the end of the quoted period of validity but may be
extended or cancelled as necessary and amended if the conditions change.
9B.2 10°C or more is present in the lowest levels of the atmosphere up to 1000 feet above
ground level. The message, for the information of departing aircraft, remains in force until
it is cancelled.
9B.3 The service is provided only to those aerodromes from which routine surface air
temperature reports are available.
10.2 As required by CAP 782, appropriate on-the-job training for meteorological and ATS
personnel shall be organised periodically with the objective of familiarising or updating
personnel with their respective functions, as well as processes and procedures to be
followed, in the event of a volcanic eruption resulting in volcanic ash affecting aeronautical
operations.
SECTION 7: CHAPTER 2
Telecommunications Services
1A.2 Access to original records is limited to protect from damage the very important evidence
which they may contain. The extent to which recordings are available is described in
Section 6.
2B.2 Daily periods (normally less than one hour) are not necessarily published but before
switching off a facility the maintenance staff will communicate with the ATC unit to ensure,
as far as can be ascertained, that it is not being used or about to be used by aircraft.
2B.3 Should weather or traffic conditions indicate that a facility is likely to be needed during a
specified maintenance period, the controller shall contact the DEO as early as possible to
arrange for maintenance to be carried out at a more convenient time.
2B.4 When a request for a particular facility is received for an aircraft due to arrive during a
maintenance period, the controller shall consider the weather and alternate facilities
available to the aircraft before asking the DEO to defer maintenance.
2C. Testing
2C.1 The DEO may on occasions request that an aircraft be asked to carry out a test of a
facility. Such tests are of importance, and controllers shall always endeavour to arrange
for them to be carried out, subject to weather and traffic conditions. However, new
installations, until declared operationally serviceable, and existing ones requiring
calibration after unserviceability, may only be flight tested by aircraft approved by the
CAA.
4. Serviceability of Equipment
4.1 Controllers shall report defects in the serviceability of any telecommunication facility to the
DEO. If appropriate, detailed reporting procedures should be incorporated in MATS Part
2.
4.2 Ground fault reports made by aircrew members should be passed to the DEO
immediately. If an aircrew member criticises any part of the telecommunications
organisation, controllers shall not discuss the matter but refer it to the DEO. If successive
reports from aircraft confirm the fault but the ground indications suggest that the facility is
serviceable, the DEO and the senior controller are to decide, in consultation, the new
status of the facility.
4.3 Control room equipment should not be tampered with in an attempt to investigate or
remedy a fault.
4.4 Unserviceable telephone equipment should be reported to the DEO except where MATS
Part 2 states otherwise.
4.5 The standby RTF equipment and emergency telephone shall be tested at regular intervals
as agreed with the DEO. These should be at least daily.
6A.2 Where necessary, post-accident flight inspections will be arranged by the DEO or the
Aerodrome Operator.
SECTION 7: CHAPTER 3
1. Introduction
1.1 The function of the Aeronautical Information Service (AIS) is to:
(1) collect, collate, edit and disseminate Aeronautical Information, necessary for the
safety and efficiency of air navigation, or interested parties. This includes CAA,
ANSPs, Aircraft Operators, aircrew, flying clubs and other aviation related
organisations;
1.2 The effectiveness and efficiency of AIS is highly dependent upon the accuracy and timely
provision of raw data. AIS do not originate information, raw data is provided by the
authority responsible for the operation of the various facilities and services such as
government departments, MoD, aerodrome and facility operators and the CAA.
2. AIS Office
2.1 The tasks of AIS can be categorised under three distinct headings.
(1) preparation and issue of UK civil and military NOTAM via AFTN;
(3) dissemination of AIS data to enable the production of Pre-flight Information Bulletins
(PIBs). These may be obtained via www.ais.org.uk.
2C.2 This information is used to prepare the UK Integrated Aeronautical Information Package
(IAIP) which consists of the following elements:
(1) AIP including amendment services (AIRAC and Non-AIRAC permanent changes);
(2) AIP Supplements (normally temporary information of long duration, or where there is
extensive text and/or graphics);
(3) AICs, information of technical or legislative matters, that does not qualify for
inclusion into the AIP.
2C.3 The Publications Department is also responsible for the maintenance and updating of the
Random Flight Plan AFTN Address Book. This online guide is published on the AIS
website as an aid to pre-flight planning and contains guidance on the addressing of flight
plans
2D.2 The Overseas Non-Scheduled Flight Clearance Guide is published by AIS as an aid to
pre-flight briefing and planning by non-scheduled operators for obtaining over-flight and
diplomatic clearance over foreign states. Amending the Aeronautical Information
Publication.
3.2 These amendments will be published every 28 days and in accordance with the AIRAC
Schedule.
5.2 For up to date information on the organisation and services of AIS refer to UK AIP (GEN)
section.
7A.2 A NOTAM shall be originated and issued promptly whenever the information to be
distributed is of a temporary nature and of short duration or when operationally significant
permanent or temporary changes of long duration are made at short notice, except for
extensive text and/or graphics. The ICAO Aeronautical Information Services Manual
Doc.8126 details the circumstances and the type of information that may be promulgated
by NOTAM.
e.g. ATSU, Aerodrome Operator. The proposal should preferably be transmitted by AFTN
to AIS (EGGNYNYX) or by fax (0208 557 0054).
Example Meaning
SECTION 8: CHAPTER 1
1. Watchkeeping Rosters
1.1 A watchkeeping roster shall be prepared by the senior controller at each ATSU. The roster
should be promulgated not later than the 20th day of each month and shall show the
hours of watch-keeping and hours of duty required of individual controllers throughout the
following month.
3. Taking-Over Watch
3.1 MATS Part 2 shall contain details of any specific procedures applicable to the taking- over
of watch by controllers at a particular unit. However, as a minimum, prior to taking-over
watch, controllers shall:
(1) ensure that they are fully conversant with the latest promulgated orders, instructions,
notices and signals; with particular reference, where appropriate, to the
serviceability of the aerodrome and its facilities. Note should be taken of details
regarding any Royal, Special or NDS flights expected during the period of their
watch;
(2) obtain full information regarding the weather situation and tendencies for the period
of their watch. This may be accomplished by a study of forecasts and prognostic
charts supplied routinely by the Meteorological Office and if clarification is
necessary, supplemented by a briefing from the designated forecast unit;
(3) familiarise themselves with the serviceability of all equipment under their charge and
liable to be used during the period of their watch;
(4) ensure that they have a full understanding of the prevailing air traffic situation, with
particular reference to separation standards.
3.2 Having completed these procedures, controllers shall sign the ATC Watch Log as having
taken-over watch. This signature shall imply that items 1. to 4. above have been complied
with and that the controller taking-over watch has assumed all the defined responsibilities
of the controller handing-over watch, including the safe custody of equipment and any
secret or confidential documents within the place of duty.
3.3 At stations where more than one controller is employed at one time on aerodrome,
approach, or area control duties, the ATC Watch Log shall be signed by the supervisor or
senior controller on duty. Other controllers shall record taking over their specific duties as
described in MATS Part 2.
4. Handing-Over Watch
4.1 MATS Part 2 shall contain details of any specific procedures applicable to the handing-
over of watch by controllers at a particular unit. Controllers handing-over watch shall
ensure that they provide their successor with the fullest possible information regarding the
prevailing traffic situation; including any items of specific interest or urgency that have
influenced the development of the situation and that may have a bearing on the progress
of the ensuing watch. Where pictorial displays are in operation they shall give a true
presentation of the traffic situation.
4.2 There may be occasions when, in the interests of safety or continuity of operation, it is
more appropriate for the controller handing-over to remain on duty to complete any
associated actions, subsequent reports and records rather than transfer the responsibility
for completion to another controller. Notwithstanding the fact that the watch roster defines
the appointed time to hand-over, the controller handing-over watch shall remain on duty
until such time as this responsibility has been discharged.
4.3 When the controller taking-over is fully conversant with the air traffic situation and is
prepared to assume full responsibility for the watch, the controller handing-over shall sign
the ATC Watch Log as handed-over watch.
5.2 Controllers taking-over should be alert to the possibility of errors and omissions in the
information being provided and must verify the data transferred to them by a thorough
check of the situation display, flight progress strips and any other relevant information.
Only when they are completely satisfied that they have a total awareness of the situation,
should they indicate to the controller handing-over that they are ready to accept
responsibility for the operational position. On the occasions when controllers hand-over a
busy and complex situation, they should remain available adjacent to the position for a
short period following the hand-over. This will enable the accepting controller to seek
immediate clarification of any points that may arise during this time.
7. Visitors
7.1 No unauthorised person shall be allowed access to an ATC operations room. Before
bringing authorised visitors into the control room a check shall be made with the senior
controller as to whether the traffic situation makes it convenient to do so. At no time shall
visits be allowed to interfere with the smooth running of the watch.
8. Clocks
8.1 Clocks in control rooms shall indicate UTC.
9. Publications
9.1 The following documents are to be available for immediate reference at operational
control positions:
(1) CAP 493 Manual of Air Traffic Services Part 1, including current Supplementary
Instructions;
9.2 ATC units should, if deemed by the unit to be necessary and appropriate, have available
for immediate reference at operational control positions the following documents. In
considering the option to make available these documents, ATC units shall consider their
day to day task and historical need to access such information.
(2) ICAO Doc. 8643 Aircraft Type Designators (available free of charge from
www.icao.int/anb/ais/8643/index.cfm);
(3) ICAO Doc. 8585 Aircraft Operating Agencies, Aeronautical Authorities and Services.
9.3 The following documents are to be available in the operational environment/control room:
(5) Air Navigation Order, Air Navigation (General) Regulations and Rules of the Air
Regulations;
9.4 CAP 670 specifies the documents that are to be available at the ATSU.
9.5 Documents are to be correctly amended and, unless otherwise approved by the CAA, be
in a conventional printed form. Requirements for the keeping of documents in electronic
format are detailed in CAP 670.
10.2 Whatever the format used to maintain the ATC Watch Log, it shall include the name of the
ATC unit, the period for which the log contains entries and shall be capable of providing a
documentary record of entries made.
10.3 An ATC Watch Log shall permit descriptive text associated with a particular date and time
(in UTC) to be recorded and enable the identity of the author to be established. Entries
shall be made in chronological order and, as far as possible, concurrently with the events
being recorded. Entries should be of sufficient detail to enable subsequent investigation of
events to have a complete understanding of actions taken by ATC.
(2) essential aerodrome information and changes to runway in use (at aerodrome-
based units);
(4) details of reportable events such as aircraft accidents, incidents and AIRPROXs;
(6) hand-over of responsibility for providing ATC services and, at units not operating
throughout the 24-hour period, times of opening and closing of watch.
10.5 An ATC Watch Log shall normally be maintained in each control room or in association
with each operational control position. When approved by the CAA and where a suitable
unit management structure exists, a single ATC Watch Log may be maintained in respect
of more than one control room or operational position.
10.6 Measures shall be taken to ensure that entries made in an ATC Watch Log cannot
subsequently be altered or be tampered with in any other way.
10.7 The method by which the ATC Watch Log is managed and entries made shall be detailed
in MATS Part 2.
12.2 At ATSUs which do not utilise handwritten log books as ATC Watch Logs, MATS Part 2
shall include procedures to ensure that the entries required to be impounded are extracted
from the ATC Watch Log and are no longer accessible to unauthorised readers.
12.3 Procedures by which the authenticity and integrity of log entries are attested, if required,
shall be documented.
Table 1:
APPENDIX A
(a) Standard Pressure Setting (1013.25 hPa) – ICAO Doc 7488 Manual of the Standard
Atmosphere and EASA Certification Specification – Definitions.
(b) Assumed value of 27.3 ft per hPa derived from a linear correction which is applied to
corrected barometric altitudes and confirmed as being utilised in aircraft and ATS
systems.
2. QNE Values
2.1 During conditions of exceptionally low atmospheric pressure it is not possible to set QFE
or QNH on some aircraft altimeters. In these circumstances an aerodrome or runway QNE
can be requested. The QNE is the reading in feet on an altimeter with the sub-scale set to
1013.2 hPa when the aircraft is at aerodrome or touchdown elevation.
Table 2:
QFE
Aerodrome/
0 1 2 3 4 5 6 7 8 9
Threshold
(Hectopascals)
970 1202 1174 1146 1117 1089 1061 1033 1005 977 948
960 1486 1458 1429 1401 1372 1344 1315 1287 1259 1230
950 1773 1744 1715 1687 1658 1629 1601 1572 1543 1515
940 2062 2033 2004 1975 1946 1917 1888 1859 1830 1802
930 2353 2324 2295 2265 2236 2207 2178 2149 2120 2091
920 2647 2618 2588 2559 2529 2500 2470 2441 2412 2382
910 2944 2914 2884 2855 2825 2795 2766 2736 2706 2677
900 3243 3213 3183 3153 3123 3093 3066 3033 3003 2974
Adjustment for decimal fractions
(1) enter first column at the figure 940 and follow this line to column headed 3. Read off
result at point of intersection, in this case 1975 feet.
(2) refer to lower table if original QFE contains a fractional figure, 0.8 in this example,
and apply the difference as shown – i.e. subtract 23 feet. QNE = 1975 – 23 = 1952
feet.
3. Conversion tables
Table 3: For converting Hectopascals to Inches of Mercury (Hg) 940.0 – 974.9 hPa
Tenths hPa: .0 .1 .2 .3 .4 .5 .6 .7 .8 .9
(Hecto-
pascals) Inches Hg
940 27.75 27.76 27.76 27.76 27.77 27.77 27.77 27.77 27.78 27.78
941 27.78 27.79 27.79 27.79 27.79 27.80 27.80 27.80 27.81 27.81
942 27.81 27.82 27.82 27.82 27.82 27.83 27.83 27.83 27.84 27.84
943 27.84 27.84 27.85 27.85 27.85 27.86 27.86 27.86 27.87 27.87
944 27.87 27.87 27.88 27.88 27.88 27.89 27.89 27.89 27.89 27.90
945 27.90 27.90 27.91 27.91 27.91 27.92 27.92 27.92 27.92 27.93
946 27.93 27.93 27.94 27.94 27.94 27.95 27.95 27.95 27.95 27.96
947 27.96 27.96 27.97 27.97 27.97 27.97 27.98 27.98 27.98 27.99
948 27.99 27.99 28.00 28.00 28.00 28.00 28.01 28.01 28.01 28.02
949 28.02 28.02 28.02 28.03 28.03 28.03 28.04 28.04 28.04 28.05
950 28.05 28.05 28.05 28.06 28.06 28.06 28.07 28.07 28.07 28.08
951 28.08 28.08 28.08 28.09 28.09 28.09 28.10 28.10 28.10 28.10
952 28.11 28.11 28.11 28.12 28.12 28.12 28.13 28.13 28.13 28.13
953 28.14 28.14 28.14 28.15 28.15 28.15 28.15 28.16 28.16 28.16
954 28.17 28.17 28.17 28.18 28.18 28.18 28.18 28.19 28.19 28.19
955 28.20 28.20 28.20 28.21 28.21 28.21 28.21 28.22 28.22 28.22
956 28.23 28.23 28.23 28.23 28.24 28.24 28.24 28.25 28.25 28.25
957 28.26 28.26 28.26 28.26 28.27 28.27 28.27 28.28 28.28 28.28
958 28.28 28.29 28.29 28.29 28.30 28.30 28.30 28.31 28.31 28.31
959 28.31 28.32 28.32 28.32 28.33 28.33 28.33 28.33 28.34 28.34
960 28.34 28.35 28.35 28.35 28.36 28.36 28.36 28.36 28.37 28.37
961 28.37 28.38 28.38 28.38 28.39 28.39 28.39 28.39 28.40 28.40
962 28.40 28.41 28.41 28.41 28.41 28.42 28.42 28.42 28.43 28.43
963 28.43 28.44 28.44 28.44 28.44 28.45 28.45 28.45 28.46 28.46
964 28.46 28.46 28.47 28.47 28.47 28.48 28.48 28.48 28.49 28.49
965 28.49 28.49 28.50 28.50 28.50 28.51 28.51 28.51 28.52 28.52
966 28.52 28.52 28.53 28.53 28.53 28.54 28.54 28.54 28.54 28.55
967 28.55 28.55 28.56 28.56 28.56 28.57 28.57 28.57 28.57 28.58
968 28.58 28.58 28.59 28.59 28.59 28.59 28.60 28.60 28.60 28.61
969 28.61 28.61 28.62 28.62 28.62 28.62 28.63 28.63 28.63 28.64
970 28.64 28.64 28.65 28.65 28.65 28.65 28.66 28.66 28.66 28.67
971 28.67 28.67 28.67 28.68 28.68 28.68 28.69 28.69 28.69 28.70
972 28.70 28.70 28.70 28.71 28.71 28.71 28.72 28.72 28.72 28.72
973 28.73 28.73 28.73 28.74 28.74 28.74 28.75 28.75 28.75 28.75
974 28.76 28.76 28.76 28.77 28.77 28.77 28.77 28.78 28.78 28.78
Table 4: For converting Hectopascals to Inches of Mercury (Hg) 975.0 – 999.9 hPa
Tenths
.0 .1 .2 .3 .4 .5 .6 .7 .8 .9
hPa:
(Hecto-
pascals) Inches Hg
975 28.79 28.79 28.79 28.80 28.80 28.80 28.80 28.81 28.81 28.81
976 28.82 28.82 28.82 28.83 28.83 28.83 28.83 28.84 28.84 28.84
977 28.85 28.85 28.85 28.85 28.86 28.86 28.86 28.87 28.87 28.87
978 28.88 28.88 28.88 28.88 28.89 28.89 28.89 28.90 28.90 28.90
979 28.90 28.91 28.91 28.91 28.92 28.92 28.92 28.93 28.93 28.93
980 28.93 28.94 28.94 28.94 28.95 28.95 28.95 28.96 28.96 28.96
981 28.96 28.97 28.97 28.97 28.98 28.98 28.98 28.98 28.99 28.99
982 28.99 29.0 29.0 29.0 29.01 29.01 29.01 29.01 29.02 29.02
983 29.02 29.03 29.03 29.03 29.03 29.04 29.04 29.04 29.05 29.05
984 29.05 29.06 29.06 29.06 29.06 29.07 29.07 29.07 29.08 29.08
985 29.08 29.09 29.09 29.09 29.09 29.10 29.10 29.10 29.11 29.11
986 29.11 29.11 29.12 29.12 29.12 29.13 29.13 29.13 29.14 29.14
987 29.14 29.14 29.15 29.15 29.15 29.16 29.16 29.16 29.16 29.17
988 29.17 29.17 29.18 29.18 29.18 29.19 29.19 29.19 29.19 29.20
989 29.20 29.20 29.21 29.21 29.21 29.21 29.22 29.22 29.22 29.23
990 29.23 29.23 29.24 29.24 29.24 29.24 29.25 29.25 29.25 29.26
991 29.26 29.26 29.27 29.27 29.27 29.27 29.28 29.28 29.28 29.29
992 29.29 29.29 29.29 29.30 29.30 29.30 29.31 29.31 29.31 29.32
993 29.32 29.32 29.32 29.33 29.33 29.33 29.34 29.34 29.34 29.34
994 29.35 29.35 29.35 29.36 29.36 29.36 29.37 29.37 29.37 29.37
995 29.38 29.38 29.38 29.39 29.39 29.39 29.40 29.40 29.40 29.40
996 29.41 29.41 29.41 29.42 29.42 29.42 29.42 29.43 29.43 29.43
997 29.44 29.44 29.44 29.45 29.45 29.45 29.45 29.46 29.46 29.46
998 29.47 29.47 29.47 29.47 29.48 29.48 29.48 29.49 29.49 29.49
999 29.50 29.50 29.50 29.50 29.51 29.51 29.51 29.52 29.52 29.52
Table 5: For converting Hectopascals to Inches of Mercury (Hg) 1000.0 – 1024.9 hPa
Tenths hPa: .0 .1 .2 .3 .4 .5 .6 .7 .8 .9
(Hecto-
pascals) Inches Hg
1000 29.53 29.53 29.53 29.53 29.54 29.54 29.54 29.55 29.55 29.55
1001 29.55 29.56 29.56 29.56 29.57 29.57 29.57 29.58 29.58 29.58
1002 29.58 29.59 29.59 29.59 29.60 29.60 29.60 29.60 29.61 29.61
1003 29.61 29.62 29.62 29.62 29.63 29.63 29.63 29.63 29.64 29.64
1004 29.64 29.65 29.65 29.65 29.65 29.66 29.66 29.66 29.67 29.67
1005 29.67 29.68 29.68 29.68 29.68 29.69 29.69 29.69 29.70 29.70
1006 29.70 29.71 29.71 29.71 29.71 29.72 29.72 29.72 29.73 29.73
1007 29.73 29.73 29.74 29.74 29.74 29.75 29.75 29.75 29.76 29.76
1008 29.76 29.76 29.77 29.77 29.77 29.78 29.78 29.78 29.78 29.79
1009 29.79 29.79 29.80 29.80 29.80 29.81 29.81 29.81 29.81 29.82
1010 29.82 29.82 29.83 29.83 29.83 29.84 29.84 29.84 29.84 29.85
1011 29.85 29.85 29.86 29.86 29.86 29.86 29.87 29.87 29.87 29.88
1012 29.88 29.88 29.89 29.89 29.89 29.89 29.90 29.90 29.90 29.91
1013 29.91 29.91 29.91 29.92 29.92 29.92 29.93 29.93 29.93 29.94
1014 29.94 29.94 29.94 29.95 29.95 29.95 29.96 29.96 29.96 29.96
1015 29.97 29.97 29.97 29.98 29.98 29.98 29.99 29.99 29.99 29.99
1016 30.0 30.0 30.0 30.01 30.01 30.01 30.02 30.02 30.02 30.02
1017 30.03 30.03 30.03 30.04 30.04 30.04 30.04 30.05 30.05 30.05
1018 30.06 30.06 30.06 30.07 30.07 30.07 30.07 30.08 30.08 30.08
1019 30.09 30.09 30.09 30.09 30.10 30.10 30.10 30.11 30.11 30.11
1020 30.12 30.12 30.12 30.12 30.13 30.13 30.13 30.14 30.14 30.14
1021 30.15 30.15 30.15 30.15 30.16 30.16 30.16 30.17 30.17 30.17
1022 30.17 30.18 30.18 30.18 30.19 30.19 30.19 30.20 30.20 30.20
1023 30.20 30.21 30.21 30.21 30.22 30.22 30.22 30.22 30.23 30.23
1024 30.23 30.24 30.24 30.24 30.25 30.25 30.25 30.25 30.26 30.26
Table 5: For converting Hectopascals to Inches of Mercury (Hg) 1025 – 1049.9 hPa
Tenths hPa: .0 .1 .2 .3 .4 .5 .6 .7 .8 .9
(Hecto-
pascals) Inches Hg
1025 30.26 30.27 30.27 30.27 30.28 30.28 30.28 30.28 30.29 30.29
1026 30.29 30.30 30.30 30.30 30.30 30.31 30.31 30.31 30.32 30.32
1027 30.32 30.33 30.33 30.33 30.33 30.34 30.34 30.34 30.35 30.35
1028 30.35 30.35 30.36 30.36 30.36 30.37 30.37 30.37 30.38 30.38
1029 30.38 30.38 30.39 30.39 30.39 30.40 30.40 30.40 30.40 30.41
1030 30.41 30.41 30.42 30.42 30.42 30.43 30.43 30.43 30.43 30.44
1031 30.44 30.44 30.45 30.45 30.45 30.46 30.46 30.46 30.46 30.47
1032 30.47 30.47 30.48 30.48 30.48 30.48 30.49 30.49 30.49 30.50
1033 30.50 30.50 30.51 30.51 30.51 30.51 30.52 30.52 30.52 30.53
1034 30.53 30.53 30.53 30.54 30.54 30.54 30.55 30.55 30.55 30.56
1035 30.56 30.56 30.56 30.57 30.57 30.57 30.58 30.58 30.58 30.59
1036 30.59 30.59 30.59 30.60 30.60 30.60 30.61 30.61 30.61 30.61
1037 30.62 30.62 30.62 30.63 30.63 30.63 30.64 30.64 30.64 30.64
1038 30.65 30.65 30.65 30.66 30.66 30.66 30.66 30.67 30.67 30.67
1039 30.68 30.68 30.68 30.69 30.69 30.69 30.69 30.70 30.70 30.70
1040 30.71 30.71 30.71 30.72 30.72 30.72 30.72 30.73 30.73 30.73
1041 30.74 30.74 30.74 30.74 30.75 30.75 30.75 30.76 30.76 30.76
1042 30.77 30.77 30.77 30.77 30.78 30.78 30.78 30.79 30.79 30.79
1043 30.79 30.80 30.80 30.80 30.81 30.81 30.81 30.82 30.82 30.82
1044 30.82 30.83 30.83 30.83 30.84 30.84 30.84 30.84 30.85 30.85
1045 30.85 30.86 30.86 30.86 30.87 30.87 30.87 30.87 30.88 30.88
1046 30.88 30.89 30.89 30.89 30.90 30.90 30.90 30.90 30.91 30.91
1047 30.91 30.92 30.92 30.92 30.92 30.93 30.93 30.93 30.94 30.94
1048 30.94 30.95 30.95 30.95 30.95 30.96 30.96 30.96 30.97 30.97
1049 30.97 30.97 30.98 30.98 30.98 30.99 30.99 30.99 31.00 31.00
Note: Uses density of mercury at 0ºC of 13595.1 kg/m³ and acceleration of gravity 9.80665 m/s².
APPENDIX B
1. Categories
1.1 The UK wake turbulence categories differ from those of ICAO. In the UK, aircraft are
divided into five categories for approach, and four categories for departure, according to
their Maximum Take-off Mass (MTOM) in kg as described below.
Table 1:
Note: The medium category is not split for departure wake turbulence separation.
(1) Heavy to Medium (Upper Medium in approach): B707; DC8; VC10; IL62.
1.3 The differences between ICAO and UK criteria do not affect the composition of flight plans
which should be completed in accordance with ICAO PANS-ATM. The wake turbulence
category of an aircraft should be indicated on the flight plan (item 9) as J (A380-800), H, M
or L.
1.4 UK wake turbulence categories for common aircraft types are shown in the table below.
Table 2:
2.2 For the purposes of separation in the approach or departure phases, within the UK, and
regardless of the weight category as entered on the flight plan, aircraft 40,000 kg or less
and more than 17,000 kg are treated as Small. Aircraft of 17,000 kg or less MTOM are
treated as Light. Helicopters such as the Eurocopter AS-332 Super Puma or larger are
treated as Small.
2.3 The Airbus A380-800, whilst falling within the Heavy category, has additional wake
turbulence separation criteria applied. Apart from the additional criteria identified, the
A380-800 is treated as a Heavy category aircraft in all other circumstances.
2.4 Aircraft with a MTOM of 136,000 kg or greater are required to be announced as ‘Heavy’ or
‘Super’ in the case of the A380, in the initial call to each ATSU. In the cases stated, where
specific aircraft have been reclassified from the Heavy category, this initial contact
announcement will not be required in the UK, as these aircraft types will be considered as
Medium (Upper Medium on approach).
APPENDIX C
1. Summary of Contents
(1) Blip Strength
1.1 The operating instructions for radio and radar equipment are detailed in MATS Part 2.
2. Blip Strength
2.1 The strength of radar blips is detailed in the table below. These values should be used
whenever controllers are required to record blip strength.
Table 1:
}
Strength 2 Acceptable Discernible blip. No persistence
(2) Routine flight inspection at specific intervals to check that facilities are operating
within tolerances;
(3) Special flight inspection in addition to routine flight inspection whenever the
performance of a facility is suspect and airborne measurement is required. This may
affect all or part of the facility;
3B.2 Weather conditions are assessed by the flight inspection organisation and the final
decision on whether or not to proceed rests with the captain of the flight inspection
aircraft. Unexpected deteriorations of weather of more than a temporary nature are to be
reported to the appropriate flight inspection organisation or directly to the captain if the
aircraft is already en route.
3C. Priority
3C.1 Whenever possible the flight inspection should be arranged to cause the minimum of
interference to other aircraft. The senior controller is to discuss the degree of urgency for
a flight inspection with the DEO. The weather, traffic density, alternative aids and time
available before dusk are to be taken into account when deciding upon any priority to be
given to the flight inspection aircraft. This may be necessary if the flight inspection is likely
to become overdue.
3C.2 Flight inspection aircraft may, where necessary, be allocated category E priority en route
and should be fitted into the traffic pattern upon arrival at the aerodrome. Short delays to
other aircraft may result, but this is preferable to the withdrawal of an aid because the
flight inspection is overdue.
3E.2 In reasonable time before a flight inspection is conducted the unit should obtain a detailed
brief from the organisation conducting the inspection with regard to the flight profiles to be
flown.
(4) Details of any required protection of the navigational aid signal in space.
3E.4 The unit should establish with the flight inspection organisation a system to identify the
particular profile to be flown so as to avoid excessive RTF. For example:
Table 2:
APPENDIX D
1. Introduction
1.1 Data showing the progress of flights under the jurisdiction of an ATC unit is to be
displayed in a manner approved by the CAA.
2. Display Systems
2.1 Flight data may be displayed using a variety of systems. Systems should be capable of
displaying to the controller sufficient information to enable a safe air traffic service to be
provided and to permit a record to be made of ATC co-ordination agreements and of
instructions or information passed to or received from the pilot.
2.2 This information acts as an aide memoir to the controller and assists when the
responsibility for the operating position is transferred from one controller to another. Flight
data may also be used, for example, following an incident or accident, to assist in
establishing the course of events that led to the occurrence.
2.3 The flight data display shall be updated immediately whenever necessary to reflect the
current traffic and control situation. In order to ensure that all relevant ATC actions are
reflected in the data display, it is essential that agreements made during controller to
controller communication, whether this is effected by the use of recorded telephone lines
or intercom systems or by face to face verbal co-ordination, are indicated on the flight data
display. All items such as levels, pertinent traffic, headings and/or speeds must be
recorded on the data displays of both controllers involved. This is particularly important in
respect of agreements made between controllers that do not result in an instruction or
other communication to a pilot.
2.4 The method to be used to display flight data and to record ATC co-ordination agreements
and instructions or information passed to or received from pilots shall be consistent at
each individual unit and is to be described in MATS Part 2.
different types of flight. Typically, flight data relating to arriving flights is displayed on buff
coloured strips, departing flights on blue coloured strips, local flights on pink coloured
strips and transit flights on green coloured strips.
3A.2 The typical locations in which information is recorded on each type of strip is shown
below.
3B.2 Additional strips describing common activities or situations, e.g. ‘Work in Progress’,
‘Runway Blocked’, Airspace delegation, ‘Low Visibility Procedures in force’ and
Danger/Restricted airspace activity, should be provided. Such strips should be displayed
in an appropriate location within the controller’s work area to denote information that may
affect the service provided by the controller.
3B.3 The strip management procedures, including the layout of the strip board and, in
particular, the method used to indicate that an aircraft has been cleared to use the runway
(or that it is in some other way in use), are to be described in MATS Part 2.
3D. Abbreviations
3D.1 Unless otherwise approved by the CAA, abbreviations published by ICAO should be used
whenever possible for recording data on flight progress strips. The following documents
include commonly used abbreviations:
3D.2 Any abbreviations that are specific to the unit, e.g. abbreviations to denote a VRP or local
route, should be described in MATS Part 2.
5. Symbols
Maintain →
M Slot time
Climb 1,000 ft below (aircraft)
↑(a/c callsign)
1
No delay expected
(for use with data transfer systems) F
APPENDIX E
1. Introduction
1.1 Radiotelephony provides the means by which pilots and ground personnel communicate
with each other. Used properly, the information and instructions transmitted are of vital
importance in assisting in the safe and expeditious operation of aircraft. However, the use
of non- standard procedures and phraseology can cause misunderstanding.
Incidents and accidents have occurred in which a contributing factor has been the
misunderstanding caused by the use of non-standard phraseology. The importance of
using correct and precise standard phraseology cannot be over-emphasised.
1.2 The United Kingdom Radiotelephony Manual (CAP 413) is the authoritative reference for
all users of RTF and includes examples of communication between pilots and controllers.
2. Distracting Conversations
2.1 Non-operational and other conversations have the potential to distract a controller from
their primary task of providing a safe air traffic service. Examples include telephone
conversations with external agencies, such as airline representatives, and discussions
between controllers conducted on the telephone, intercom or, in some cases, face to face,
following an unplanned traffic situation.
2.3 Discussions regarding unplanned traffic situations, which may include incidents and
alleged breaches of procedure, are not to be conducted from operational positions. If
appropriate, only brief details of the occurrence should be exchanged between the
controllers involved. If there is a need to discuss the matter further, this should be
deferred to a time when all the personnel affected are relieved from their operational
duties. Where staffing levels permit, unit management staff that are not working at an
operational position should make arrangements for further discussions.
3. Landline Telephone
3.1 It is correct procedure for controllers to announce identity on all telephone calls: with
incoming calls it is the opening remark and with outgoing calls the reply to the recipient’s
announcement of identity.
3.2 It is just as important that this procedure is not relaxed for direct telephone lines because
mistaken identity can occur when another line has been inadvertently left open from a
previous call. Announcing identity on outgoing calls when using direct telephone lines is
not required at those units where equipment and labelling ensure that mistaken identity
cannot occur. Specific details are to be documented in MATS Part 2.
3.3 The identity to be used is that of the function relative to the telephone extension being
used. On outside calls the identity should be given in full, for example “London Control
Sector 21 Planner” but on direct lines, where it will require no further amplification, it may
be abbreviated to “Sector 21 Planner”.
3.4 Controllers shall read back any operationally significant information contained in
telephone (and intercom) co-ordination messages including:
(1) Levels;
(2) Headings;
(7) Pressure Settings, including units when value is below 1000 hPa;
(8) Frequencies;
4.2 Where messages of a technical and complicated nature are involved it may be found
advisable to permit direct speech between the originator of the message and the pilot. In
such cases the company’s representative may be permitted to use the RTF himself
provided that his identity is announced before the message is passed and that the
controller continues to monitor the frequency.
4.3 A message affecting the safety of an aircraft in flight, e.g. bomb warning, suspected
damage to the aircraft, etc., is to be passed to the commander immediately using the
company representative’s precise wording. An abbreviation or precis could be
misunderstood and lead to a wasteful operation or even a dangerous situation.
4.4 Prolonged company messages could prevent controllers from providing a safe air traffic
service and the use of discrete frequency for the passing of such messages should be
considered.
(1) Levels;
(2) Headings;
(7) Pressure Settings, including units when value is below 1000 hPa;
(8) Frequencies;
ATTACHMENT TO APPENDIX E
Phraseology
CO-ORDINATION (Direction of flight) ETD (time) flight level requested (number) aircraft
BETWEEN UNITS identification (callsign) type (designation) TAS (departure aerodrome)
Flight Plan details (route) (destination) (flight plan number).
Clearance request (Aerodrome) request clearance for (a/c identity).
Airways clearance Clearance (a/c identity) cleared to (clearance limit) (level) (SID) squawk
(four digits).
28 December 2017 Attachment to Appendix E: List of Standard Landline Telephone Phrases - Page 1
CAP 493
Phraseology
Estimate Message (Direction of flight) estimate (a/c identity) squawking (four digits) (type)
and Revision estimated over (significant point) at (time) (level) speed (filed TAS) via
(route) (Clearance limit if other than destination).
28 December 2017 Attachment to Appendix E: List of Standard Landline Telephone Phrases - Page 2
CAP 493
APPENDIX F
(1) Ground speed – the actual speed of the aircraft over the surface of the earth. This
equates to TAS corrected for the effects of wind
(2) True airspeed (TAS) – the actual speed of the aircraft through the air and is shown
on the flight plan and flight progress strips.
(3) Indicated airspeed (IAS) – often used by ATC for speed control and varies from the
TAS dependant on altitude, air density and temperature (see Figure 1).
(4) Mach number – TAS expressed as a fraction of the local speed of sound. The speed
of sound (Mach 1) is a function of temperature – colder (i.e. higher) equalling slower.
In international standard atmosphere (ISA) conditions, at sea level Mach 1 is a little
over 661 kt TAS, but at FL360 it has decreased to 572 kt and remains at that figure
to around FL600 – FL700 (see Figure 2).
Figure 1
Figure 2
If an aircraft climbs from sea level to FL350 at a constant Mach number of .70 then the
TAS will decrease from 463 to 400 kt. Similarly, a constant Mach number descent will
result in increasing TAS.
1.2 Due to the low air density at high altitude, airspeed indicators read less than the actual
speed of the aircraft, but at sea level there is virtually no difference between them.
Therefore, an aircraft climbing at a constant IAS will have an increasing TAS. For
example, under ISA conditions 250 kt IAS at sea level equates to 250 kt TAS, but at
FL430 an IAS of 250 kt equals a TAS of 502 kt. Conversely, if a descent is carried out at a
constant IAS the TAS will decrease as altitude is lost. (See Figure 3.)
Figure 3
Looking at a typical climb/descent profile for an MD80 the following can be observed.
1.3 The aircraft climbs at 290 kt IAS until it reaches Mach .76. It continues the climb
maintaining .76 to cruise altitude, cruises at .76 and holds that Mach speed in descent
until reaching 290 kt IAS again. As there is a speed limitation of 250 kt IAS below FL100
the initial climb will be at 250 kt IAS (289 kt TAS/Mach .45). The aircraft will then
accelerate to 290 kt IAS (334 kt TAS/Mach .52 at 10,000 feet) and then climb at this
constant indicated speed. During this climb both the TAS and Mach number will be
increasing as follows:
Table 1:
If the crew had not changed from IAS to Mach number and tried to hold 290 kt IAS all the
way to FL370, the speed at top of climb would be Mach .88 – far in excess of the
permitted limit.
1.4 In the descent, the process is reversed. The pilot will fly at Mach .76 until the IAS reaches
290 kt, which should occur around FL290. During this part of the descent the aircraft will
accelerate slightly from 245 to 290 kt IAS (435 to 445 kt TAS). In the descent from FL290
to FL100 the aircraft will be flown at a constant 290 kt IAS and the TAS will decrease from
445 to 334 kt. IAS will then be reduced to around 210 kt in preparation for configuring the
aircraft for approach. Controllers should be aware of airspeed changes according to the
stage of flight when applying speed control.
1.5 Turbulence narrows the allowable speed range of the aircraft as minimum speeds are
increased to maintain control effectiveness and maximum speeds may be reduced to
prevent damage from excessive ‘G’ loads encountered in rough air.
2.2 Considering the aircraft in the clean configuration that applies throughout the flight, except
for short periods during take-off and landing, the operational speed range is bounded by
the stall at low speed and by the maximum operating speed at high speed. (This
maximum operating speed when defined as an airspeed is designated Vmo and when a
Mach number is used, Mmo.) The stall speed is principally related to IAS and increases
with increasing weight and, to some extent, with increasing altitude. Minimum operational
speeds will allow a margin from the stall speed to permit a manoeuvre capability and
protection from short term atmospheric effects without encountering the stall.
2.3 The high speed limits of Vmo/Mmo are set at a suitable margin below the ultimate design
limits to provide protection for inadvertent speed increases due to atmospheric
disturbances or other causes. The high speed design limits may be set by structural or
handling considerations. While the pilot may fly at speeds up to Vmo/Mmo, various
performance considerations will generally preclude this except during the descent.
At high altitude and high weight an aircraft may encounter high Mach buffet when
manoeuvring at speeds below Mmo which will present an additional constraint on
maximum speed. As these are also the considerations that lead to the highest values of
low speed stall, it can be seen that the effective speed range available may be reduced
markedly with altitude. Indeed, the minimum and maximum operational speeds due to low
speed stall and high speed Mach buffet respectively, may become coincident at a
particular weight/altitude combination that is below the absolute ceiling that the aircraft
might utilise at lower weights.
2.4 Optimum climb and descent profiles are determined by various performance
characteristics and speeds close to Vmo/Mmo may frequently be flown in the descent. In
the climb, optimum speed, especially for large aircraft at high weight, can be severely
limited to give protection against the stall. This speed may also be close to, if not above,
the 250 kt ATC speed limit below 10,000 feet.
2.5 The methods at a pilot’s disposal to increase descent capability are reduction of thrust,
increase of airspeed and use of airbrakes. However, pilots are reluctant to use airbrakes,
unless absolutely necessary, due to passenger discomfort and increased fuel burn
considerations. Thus the optimum descent profile is one which permits the aircraft to
maintain cruising altitude to that point from which a gliding descent to intercept the final
approach can be made with throttles closed but with airbrakes retracted. Speed will
normally be kept high initially, often at or close to Vmo/Mmo. The pilot may have
significant flexibility over the speed at which he can safely and legally fly, but at the risk of
deviating from the optimum descent profile. Subsequent corrections to the flight path may
require the use of airbrakes or an indirect routing to final approach.
2.6 The available speed range is altered very considerably once flaps are extended. The use
of flaps is normally restricted to lower altitudes.
Once the flaps are extended the maximum permitted airspeed is significantly reduced.
However, extending flaps does delay the onset of the stall and permits lower minimum
speeds to be used. However, this again imposes fuel efficiency penalties and pilots
normally prefer to maintain a holding speed that is not less than that at which they can
safely maintain the clean (flaps retracted) configuration.
2.7 When an aircraft is heavily loaded and at a high level, its ability to change speed may, in
cases, be very limited. In the event of engine failure or other systems failures, additional
speed constraints are likely to apply. Quite apart from a reduced performance capability,
these may involve an increased minimum speed, a reduced maximum speed, or both, at
which the aircraft can be flown safely.
3.2 At high levels (FL280 and above), speed control instructions should be passed by
reference to Mach number. As a general rule of thumb, at these levels, 0.01 Mach equals
6 kt TAS. If a controller is trying to match speeds of aircraft at different levels, the same
Mach number will mean that the higher aircraft will be a little slower. An allowance of 0.01
Mach for each 2 – 3000 feet level difference will achieve a closer match in ground speed.
3.3 Unlike Mach number control, the results of allocating IAS restrictions to aircraft vary
substantially with altitude. An aircraft maintaining 280 kt IAS at FL330 will have a TAS of
459 kt while an aircraft with the same IAS at FL270 will produce a TAS of 417 kt. For
aircraft operating at the same IAS, a rule of thumb is 7 kt for each 1000 feet level
difference. Above FL240 each 10 kt of IAS equals approximately 15 kt of TAS.
3.4 The result of these differences is that when two aircraft are assigned the same Mach
number, an aircraft at a higher level will be slower but when they are assigned the same
IAS an aircraft at a higher level will be faster.
3.5 The variation in wind strength and/or direction with height is a factor to be considered
before applying any speed control. A large variation in either element can cause any
separation to be eroded very quickly.
3.6 It is important to give crews adequate notice of any speed restrictions they can expect
particularly if other descent restrictions have been applied, e.g. to be at a level at a
specified point. Aircrew plan descents at a given speed and rate so high descent rates
and low airspeeds are not normally compatible. Short notice speed restrictions issued
while descent to a target level is in progress, may cause problems for the crew.
3.7 The lack of aerodynamic drag and the presence of significant idle thrust of turbine engined
aircraft, particularly in icing conditions, make rapid descents with speed reduction
generally impracticable. Whilst piston engined aircraft do have this performance capability
by virtue of rapid engine response, propeller and airframe drag and less inertia, pilots may
not be able to exploit this advantage as reduction in engine power while descending
quickly can result in ‘shock cooling’ to the engine resulting in an expensive overhaul.
3.8 Significant speed reductions may require the pilot to level off to lose speed before
returning to the descent. Advance planning is even more important with heavy jets. At the
bottom of a high speed descent their inertia will be great and both time and distance will
be needed to reduce speed for ATC purposes.
3.9 ‘Minimum clean speed’ signifies the minimum speed at which an aircraft can be flown in a
clean configuration, i.e. without deployment of lift-augmentation devices, speed brakes or
landing gear. The use of the phrase ‘minimum clean speed’ can achieve a reduction in
aircraft speed in a very short space of time and is useful in appropriate circumstances.
However, the actual speed flown will vary depending on type, and compliance may be
affected by other factors such as local turbulence.
This instruction to fly at minimum clean speed should be given early to enable aircrew to
plan and achieve descent profiles.
3.10 A speed reduction instruction issued to a climbing aircraft may result in a temporary
increase in climb rate. The pilot is likely to raise the nose of the aircraft to allow the
airspeed to reduce and so the vertical speed will increase.
APPENDIX G
1. This table provides guidance on the calculation of crosswind component and should be
used when determining ‘out of wind runway’ operations.
APPENDIX H
Directory
Regional Managers
Southern Region Tel: 01293 573458
Aviation House Tel: (outside office hours) 07771 976394
Gatwick Airport South Fax: 01293 573 974
West Sussex, RH6 0YR Email: ats.southern.regional.office@caa.co.uk
Military
D&D Cell Tel: 01489 612 406
LATCC (Mil) LJAO Supervisor Tel: 01489 612 417
LATCC (Mil) East Supervisor Tel: (outside office hours) 01489 612 408
LATCC (Mil) North Supervisor Tel: 02380 401 509
LATCC (Mil) RAC Tel: 01489 612 172
MoD (AFO)
RAF Main Building Tel: 0207 218 9000
Whitehall
London SW1A 2HB
NATS
London ACC Watch Manager
NATS En Route Ltd Tel: 01489 612 420
Sopwith Way Swanwick Flow Management Unit (Post Box 23)
Hants SO31 7AY Tel: 01489 612 427
Fax: 01489 612 437
Ofcom
Radio Investigation Service Tel: (H24) 01462 428528
(Reporting Malicious Interference) Fax: (H24) 01462 438885
Alternative Fax: (Monday-Friday 0900-1730)
01462 428510
APPENDIX I
The eye specialist may be either an Optometrist or Ophthalmologist. It is extremely unlikely that a
laser beam exposure will result in permanent eye damage. Eye discomfort and irritation during the
exposure is common and rubbing your eye can result in abrasion that may be painful. If you have
experienced one or more of the following after a laser beam exposure consult an eye specialist.
Eye problems – swelling, pain, itching, watering, discharge, dryness or redness of the eye.
Visual disturbance – blurring, black spot, trouble reading, loss of peripheral vision, floaters, halos,
poor night vision, sensitivity to light.
These symptoms may not appear until hours after the incident and may not be related directly to
laser exposure but could reflect other eye issues perhaps not previously noticed.
Types of exposure
1- Flash blindness
A visual impairment during and after exposure to a very bright light. It may
last for seconds or minutes.
2- Glare
3- Distraction
Amsler Grid
While viewing the grid from 30 cm in
front of your eyes, please test one eye
at a time to answer the following
questions:
If you answered YES to all three questions then please turn to page 3.
If you answer NO to any of the above questions then you may wish to remove yourself from flying or
controlling duties as soon as it is safe to do so and consult an eye specialist.
In some circumstances it may be possible to have retinal damage without obvious symptoms. The
relevance of this is uncertain in the absence of abnormal visual signs (e.g. answering “yes” to all
three Amsler Grid questions on page 2) as it is unlikely to have an operational impact or be
amenable to treatment. The following is designed to aid a pilot or ATCO in deciding whether or not
an assessment should be sought with an optometrist or ophthalmologist after an exposure.
No
Did you experience flash blindness
(visual impairment during and after No
Was the laser beam green? Yes
exposure to a very bright light that 1
may last for seconds or minutes)?
Yes
No
Was the laser beam green? 2 Notes:
Did you look away / blink Yes There is a possibility of eye damage
1 2
immediately? and it is suggested that you contact an
eye specialist for further evaluation
although this does not need to be
undertaken urgently in the absence of
No
symptoms.
For further information, the British Airline Pilots Association (BALPA) have produced an advisory
information sheet which will be available on their website www.balpa.org
APPENDIX J
INDEX
Index
A
Accident Reports Sect 6 Chp 3 para 5A
Aerodrome
Closure Sect 2 Chp 1 para 25A
Restricted Operation Sect 2 Chp 1 para 25B
Service Outside Published Hours Sect 2 Chp 1 para 25C
Aerodrome Control Sect 2 Chp 1 Para 1
Arriving Aircraft Sect 2 Chp 1 para 18
Clearance Limit Sect 2 Chp 1 para 12
Co-ordination Sect 2 Chp 1 para 3
Exemptions From Separation Minima Sect 2 Chp 1 para 20
Effect of Weather on Operations Sect 2 Chp 1 para 6
Provision of Services Sect 2 Chp 1 para 1
Responsibilities Sect 2 Chp 1 para 2
Transfer of Control Sect 2 Chp 3 para 4
Aerodrome Emergency Services
Definitions of Emergency and Incidents Sect 5 Chp 7 para 5
Depletion Sect 5 Chp 7 para 3.1
Fire Fighting Categories Sect 5 Chp 7 para 3.2
Heliport Fire Fighting Categories Sect 5 Chp 7 para 8.1
Practice Exercises and Drills Sect 2 Chp 1 para 31D
Removal of Crashed Aircraft Sect 5 Chp 7 para 7
Use of 121.6 Sect 5 Chp 7 para 6
Aerodrome Inspections Sect 2 Chp 6 para 1
Aerodrome Lighting Sect 2 Chp 2 para 1
Aerodrome Operating Minima Sect 3 Chp 1 para 9D
Aerodrome Traffic Circuit Sect 2 Chp 1 para 17
Aerodrome Traffic Monitor Sect 2 Chp 1 para 21
Aerodrome Traffic Zone Sect 1 Chp 2 para 6
Aeronautical Fixed Service Sect 7 Chp 2 para 3
Aeronautical Information Service Sect 7 Chp 3 para 1
Aeronautical Mobile Service Sect 7 Chp 2 para 1
Aeronautical Rescue Co-ordination Centres Sect 5 Chp 6 para 5
Airborne Collision Avoidance System Sect 1 Chp 10 para 1
B
Ballistic Recovery Systems Sect 5 Chp 1 para 16
Balloons
Captive Sect 1 Chp 2 para 20
Flights in Controlled Airspace Sect 1 Chp 4 para 19
Basic Service Sect 1 Chp 12 para 2
Bird Strikes Sect 6 Chp 5 para 1
Bomb Warnings Sect 5 Chp 9 para 1
C
Class C Airspace
ATC procedures Sect 1 Chp 2 para 9
General Rules Sect 1 Chp 2 para 9D
Pilot Requirements Sect 1 Chp 2 para 9C
Separation Requirements Sect 1 Chp 2 para 9B
Class D Airspace
Control of VFR Flights Sect 1 Chp 5 para 3
Gliders in Class D Airspace Sect 1 Chp 5 para 4
Integration of VFR and IFR Flights Sect 1 Chp 5 para 1
Letters of Agreement Sect 1 Chp 5 para 5
Clearances
Air Traffic Control Sect 1 Chp 4 para 1
Amendments Sect 1 Chp 4 para 7
Clearance Limit Sect 1 Chp 4 para 3
Conditional Clearances Sect 1 Chp 4 para 4
Contents Sect 1 Chp 4 para 2
Route Sect 1 Chp 4 para 5
Withholding Sect 1 Chp 4 para 8
Clocks Sect 8 Chp 1 para 8
Combined Operational Position Sect 8 Chp 1 para 6
Competence Sect 8 Chp 2 para 3
Control of Surface Traffic Sect 2 Chp 1 para 10
Controller Error Sect 8 Chp 2 para 5
Controller’s Hours Sect 8 Chp 1 para 2
Controller Overload Sect 6 Chp 2 para 2
Co-ordination Sect 1 Chp 11 para 2
Aerodrome Control Sect 2 Chp 1 para 3
Approach Control Sect 3 Chp 1 para 4
D
Dangerous Goods Sect 5 Chp 1 para 11J
Deconfliction Service Sect 1 Chp 12 para 4
Disclosure of Information Sect 6 Chp 1 para 7
Distress and Diversion Cell Sect 5 Chp 1 para 9
Distress and Emergency Messages Sect 5 Chp 1 para 4
Diversions
General Sect 1 Chp 8 para 1
Approach Control Sect 3 Chp 1 para 18
Area Control Sect 4 Chp 2 para 12
E
Emergency Position Indicating Radio Beacons Sect 5 Chp 8 para 1
Essential Aerodrome Information Sect 2 Chp 1 para 8
Essential Traffic Information Sect 1 Chp 3 para 4
Estimate Messages Sect 1 Chp 4 para 11A
Expected Approach Time
General Sect 1 Chp 4 para 13
Approach Control Sect 3 Chp 1 para 16
Area Control Sect 4 Chp 2 para 11.2
F
Facilitation Sect 5 Chp 1 para 15
Final Approach Sect 3 Chp 2 para 9C
Fireworks Sect 2 Chp 3 para 5
Flight Information Service Sect 1 Chp 1 para 7
Flight Inspection Appendix C para 3
Flight Data Display Sect 1 Chp 4 para 9
Flight Levels Sect 1 Chp 7 para 2
G
Glider Operation in Class D Airspace Sect 1 Chp 5 para 4
Glider Operations in Controlled Airspace Sect 1 Chp 4 para 20
Grass Aerodromes Sect 2 Chp 1 para 9
Ground Proximity Warning System Sect 1 Chp 4 para 16
Ground Signals and Markings Sect 2 Chp 1 para 29
H
Hectopascals Sect 1 Chp 7 para 1
Helicopter Emergency Medical Service Sect 1 Chp 4 para 22
High Winds Sect 7 Chp 2 para 2E
Hijacking Sect 5 Chp 5 para 1
Holding Procedures
Area Control Sect 4 Chp 2 para 11
General Sect 3 Chp 1 para 14
Holding for Weather Improvement Sect 3 Chp 1 para 17
I/J/K
Incapacity Sect 8 Chp 2 para 10
Infringement of Legislation Sect 6 Chp 4 para 1
Military Aircraft Sect 6 Chp 4 para 5
Tracing Action Sect 6 Chp 4 para 2
Instrument Approaches Sect 3 Chp 1 para 13
Instrument Flight Cancellation Sect 1 Chp 2 para 7
Instrument Flight Rules Sect 1 Chp 2 para 5
IRVR Sect 3 Chp 3 para 3
L
Landing Sect 2 Chp 1 para 19
M
Malicious Interference to VHF Communication Sect 6 Chp 5 para 5
Mareva Injunctions Sect 1 Chp 4 para 23
Maritime Incidents Sect 6 Chp 5 para 2
Medical Emergencies Sect 1 Chp 4 para 10B
Medical Examination Sect 8 Chp 2 para 9
Meteorological Information
Transmission – Approach Control Sect 3 Chp 1 para 10
Transmission – Area Control Sect 4 Chp 5 para 3
Meteorological Services
Aerodrome Warnings Sect 7 Chp 1 para 9
Aircraft Observations Sect 7 Chp 1 para 3B
Briefing of Controllers Sect 7 Chp 1 para 1
Forecasts Sect 7 Chp 1 para 8
METAR Sect 7 Chp 1 para 6
Reports – Routine Sect 7 Chp 1 para 4
Reports – Special Sect 7 Chp 1 para 5
SIGMET Sect 7 Chp 1 para 7
Source of Information Sect 7 Chp 1 para 3
Volcanic Ash Sect 7 Chp 1 para 10
Missed Approach Instructions Sect 3 Chp 2 para 15
Movement Log Sect 8 Chp 1 para 11
N/O/P/Q
Navigation Lights Sect 1 Chp 2 para 18
Non-Deviating Status Sect 1 Chp 4 para 17
Non-Precision Approaches Sect 3 Chp 2 para 9F
NOTAM Sect 7 Chp 3 para 7
Notification of Flights Sect 1 Chp 4 para 11
Nuclear and Chemical Accidents Sect 5 Chp 8 para 3
Oceanic Area Control Sect 4 Chp 4 para 1
Overdue Aircraft
ACC Procedures Sect 5 Chp 3 para 3
Aerodrome Procedures Sect 5 Chp 3 para 2
R
Radar and Radio Aids Appendix C
Radar Control Sect 1 Chp 6 para 1C
Radio Failure Sect 5 Chp 4 para 1
Emergency Triangle Procedure Sect 5 Chp 1 para 7
Failure of Two way Radio Communications Sect 5 Chp 4 para 4
IMC Procedure for Pilots Sect 5 Chp 4 para 6
Resumption of Normal Operations Sect 5 Chp 4 para 7
Standard Procedure For Controllers Sect 5 Chp 4 para 2
VMC Procedure for Pilots Sect 5 Chp 4 para 5
Use of ATS Surveillance Systems Sect 5 Chp 4 para 3
Records
Access to Original Records Sect 6 Chp 1 para 6
ATS Sect 6 Chp 1 para 5
Disposal Sect 8, Chp 1 para 13
Regional Pressure Setting Sect 1 Chp 7 para 4
Release of Racing Pigeons Sect 2 Chp 1 para 32
Reporting Action
Accident Reports Sect 6 Chp 3 para 5
Aerodrome Sect 6 Chp 3 para 3
ACC Sect 6 Chp 3 para 4
AIRPROX Sect 6 Chp 3 para 7
Bird Strikes Sect 6 Chp 5 para 1
General Guidance Sect 6 Chp 1 para 1
Incidents on Board an Aircraft in Flight Sect 6 Chp 3 para 10
Malicious Interference to VHF Communication Sect 6 Chp 5 para 5
Maritime Incidents Sect 6 Chp 5 para 2
Serious Incident Sect 6 Chp 3 para 6
Sonic Boom Sect 6 Chp 5 para 4
S
Safety and Expedition Sect 1 Chp 1 para 10
Search Action Sect 1 Chp 2 para 17
Searchlights Sect 2 Chp 3 para 5
Secondary Surveillance Radar
Conspicuity Codes Sect 1 Chp 6 para 4F
London FIS Code Sect 1 Chp 6 para 15A
Monitoring Codes Sect 1 Chp 6 para 4G
Mode C Sect 1 Chp 6 para 10
Mode S Sect 1 Chp 6 para 5
Selected Altitude Sect 1 Chp 6 para 5C
Special Purpose Codes Sect 1 Chp 6 para 4E
SSR Code Assignment Plan Sect 1 Chp 6 para 4B
Mode A SSR Validation Sect 1 Chp 6 para 4C
Transponder Mandatory Zones Sect 1 Chp 6 para 6
Separation Standards
Aircraft Holding Sect 1 Chp 3 para 8C
Changing Levels Sect 1 Chp 3 para 5B
Departing Aircraft Sect 1 Chp 3 para 8D
Essential Traffic Information Sect 1 Chp 3 para 4
Geographical Separation Sect 1 Chp 3 para 7B
Horizontal Separation Sect 1 Chp 3 para 6
T
Take off
Awaiting Sect 2 Chp 1 para 13
Cancelling Sect 2 Chp 1 para 16
Clearance
Taxiing Sect 2 Chp 1 para 11
TCAS
Departure from ATC Clearance Sect 1 Chp 10 para 5
Effect on ATC Sect 1 Chp 10 para 3
Nuisance Advisories Sect 1 Chp 10 para 4
Phraseology Sect 1 Chp 10 para 6
Reporting Sect 1 Chp 10 para 7
Warnings Sect 1 Chp 10 para 2
Temporary Reserved Airspace Sect 4 Chp 6 para 1
Terrain Clearance
Approach Radar Sect 3 Chp 2 para 1
Surveillance Sect 1 Chp 6 para 14
Time Checks Sect 2 Chp 1 para 11.2
Traffic Information Sect 1 Chp 11 para 1
Traffic Service Sect 1 Chp 12 para 3
Transition Altitude Sect 1 Chp 7 para 5A
Transition Layer Sect 1 Chp 7 para 5C
Transition Level Sect 1 Chp 7 para 5B
Determination Appendix A
Transfer of Control
General Sect 1 Chp 4 para 12
Aerodrome Sect 2 Chp 1 para 2
Approach Sect 3 Chp 1 para 5
Transfer of Communication Sect 1 Chp 4 para 12A
Approach Sect 3 Chp 1 para 7
U/V/W/X/Y/Z
UK Flight Information Services Sect 1 Chp 12 para 1
Advisory Routes Sect 1 Chp 12 para 7
Agreements Sect 1 Chp 12 para 1F
Basic Service Sect 1 Chp 12 para 2
Deconfliction Service Sect 1 Chp 12 para 4
Procedural Service Sect 1 Chp 12 para 5
Service Principles Sect 1 Chp 12 para 1
Traffic Service Sect 1 Chp 12 para 3
Unidentified Aircraft Sect 5 Chp 2 para 3
Unidentified Flying Objects Sect 6 Chp 5 para 3
Unlawful Interference Sect 5 Chp 5 para 1
Vectoring
General Sect 1 Chp 6 para 13
To Final Approach Sect 3 Chp 2 para 9
Vertical Position Sect 1 Chp 7 para 6
Visitors Sect 8 Chp 1 para 7
Visual Approach
General Sect 3 Chp 1 para 12
Approach Radar Sect 3 Chp 2 para 9H
Visual Flight Rules Sect 1 Chp 2 para 9I
VMC Climb and Descent Sect 1 Chp 3 para 5C
Volcanic Ash Sect 7 Chp 1 para 10
Watch
Extensions Sect 2 Chp 1 para 26
Handing Over Sect 8 Chp 1 para 4
Taking Over Sect 8 Chp 1 para 3
Watchkeeping Rosters Sect 8 Chp 1 para 1
Wake Turbulence Sect 1 Chp 3 para 9
Applicability Sect 1 Chp 3 para 9B
Categorisation Appendix B
Crossing and Parallel Runways Sect 1 Chp 3 para 9H
Departures Sect 1 Chp 3 para 9F
Displaced Landing Threshold Sect 1 Chp 3 para 9I
En-Route Sect 1 Chp 3 para 9C