After December 20, 2010,

airplane operators must

ensure that all new
repairs to fatigue-critical
structure receive a damage
tolerance evaluation.

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Complying with the Aging
Airplane Safety Rule
By December 20, 2010, airlines that operate airplanes under Title 14 of the Code
of Federal Regulations (CFR) 121 or 129 must revise their U.S. Federal Aviation
Administration (FAA)-approved structural maintenance program to comply with the FAA’s
Aging Airplane Safety Rule (AASR). This revised maintenance program must include
damage-tolerance-based inspections; a means to address the effects that repairs,
alterations, and modifications may have on fatigue-critical structure and these inspections;
and a means by which all changes to the maintenance program receives FAA approval.
Boeing has developed materials to help operators comply with this new rule.

By Roxanne M. Pillo, AASR Deputy Program Manager, Fleet Support Engineering Airframe, and
Amos Hoggard, Technical Fellow (Retired), AASR Program

The Aging Aircraft Safety Act of 1991 passed Retroactive aspects to this rule require Canada. Currently, some operators of
by Congress in 1991 — and later codified by surveys of all active airplanes for the non‑U.S.-registered airplanes intend to
the FAA as the AASR — requires airlines to purpose of documenting existing repairs, voluntarily comply with the AASR.
ensure that repairs or modifications made alterations, and modifications requiring Boeing, working with the industry, has
to their airplanes are damage-tolerant. As damage tolerance inspections. Specific developed FAA-approved methods of
part of the requirement, airlines must have time periods have been established to compliance to help operators meet the
a damage-tolerance-based mainte­nance obtain the inspection requirements for terms of the new rule. The AASR-required
program in place by December 20, 2010. existing repairs, alterations, and changes are complex and require significant
This includes the development of an FAA- modifications that currently lack the revision to the processes and procedures
approved Operator Implementation Plan required damage tolerance inspections. contained in existing maintenance pro­
that contains the processes and time­lines At least 4,000 airplanes (U.S.-registered) grams. This article provides regulatory
the operator will use for obtaining and incor­ and 240 operators are affected by this new background about the new rule, key
porating maintenance actions to address rule. While only U.S.-registered airplanes provisions of the AASR, the compliance
the effects of repairs and alterations. are affected at this time, the number of method developed by the commercial
In order to comply with the AASR, affected airplanes could more than double airline industry, and the information
operators will need to reassess their if the FAA rule is adopted by other regu­ developed by Boeing to support operator
structural maintenance program and the latory agencies, including the European compliance with the new rule.
way repair approvals are being considered. Aviation Safety Agency and Transport
15
www.boeing.com/c o m m e r c ia l/ a er o ma g a zi n e
 Regulatory background and To facilitate operator compliance to December 20, 2010, that affect fatigue-
requirements the operational rules and to assist in critical structure and do not have approvals
operator development of their implemen­ indicating a damage tolerance evaluation
The AASR was published, in part, to satisfy tation plan, the FAA also has required type and the resulting damage toler­ance
the Aging Aircraft Safety Act of 1991. The certificate holders and design approval inspections require further action.
act requires air carriers to demonstrate that holders to make available certain new and Operators are expected to identify and
maintenance of an airplane’s age-sensitive updated information under 14 CFR 26, document these repairs via an airplane
parts and components has been “adequate Subpart E, including: survey. All airplanes delivered prior to
and timely enough to ensure the highest December 20, 2010, will require a survey
■■ Documents defining fatigue-critical
degree of safety.” to determine repairs to fatigue-critical struc­
structure.
The AASR requires operators to have ture that do not have damage tolerance
■■ Fatigue-critical baseline structure lists.
a damage-tolerance-based structural inspections. The operator’s implementation
■■ Fatigue-critical alteration structure lists.
maintenance program for each applicable plan will need to define how they will obtain
■■ Updated published information with
transport category airplane operated in and implement the damage tolerance
damage-tolerance-based maintenance
14 CFR 121 and U.S.-registered airplanes inspections for these repairs.
data for items affecting fatigue-critical
operated in 14 CFR 129. The requirement
structure, including: Existing alterations. Existing alterations are
extends to the fatigue-critical structure of
■■ Structural repair manuals. those installed prior to December 20, 2010,
the baseline, as-delivered airplane structure,
■■ Fleet-support service bulletins. that affect fatigue-critical structure and do
as well as to existing and future repairs and
■■ Master-change service bulletins. not have approvals indicating a damage
alterations that affect fatigue-critical struc­
■■ Supplemental type certificates. tolerance evaluation and the resulting
ture. The rule affects all Boeing 7-series,
■■ Model-specific compliance documents damage tolerance inspections require fur­
MD, and DC turbofan-powered transport
that contain a repair evaluation guideline. ther action. Operators are expected to utilize
category airplanes. Operators must comply
the information provided by Boeing or other
with this rule by December 20, 2010.
design approval holders to ensure that a
Operators are expected to develop and Key provisions affecting
operators
damage-tolerance-based maintenance
gain FAA approval of an Operator Imple­
program exists for all existing alterations.
men­tation Plan that details how the operator
will comply with the requirements of the New repair approvals to fatigue-critical
operational rules. This plan will consist of structure. As of January 11, 2008, this An industry-developed method
both new and existing operator-specific covers any new or significantly revised of compliance
processes the operator will use in repair, master-change service bulletin, or
demonstrating compliance, including: supplemental type certificate approved by Boeing participated in the Airworthiness
Boeing on behalf of the FAA required and Assurance Working Group (AAWG) to
■■ A process to identify repairs and alter­
contained damage tolerance inspections. estab­lish a method of compliance that
ations that will require damage tolerance
Operators must adopt the damage could be broadly supported by all stake­
inspections. (The FAA defines damage
tolerance provisions provided in the holders. The AAWG developed the initial
tolerance inspec­tions as maintenance
approval paperwork for these repairs and draft of the FAA’s advisory circular for this
actions necessary to detect or preclude
alterations for all new installations after rule, AC 120‑93. Boeing continues to
fatigue cracking that could contribute to
January 11, 2008. After December 20, participate in the AAWG to enable
catastrophic failure. Damage tolerance
2010, it is the operators’ responsibility to resolution and awareness of compliance
inspections are developed as a result of
ensure that all new repairs to fatigue-critical issues at an industry level throughout the
a damage tolerance evaluation.)
structure receive a damage tolerance implementation of this rule.
■■ A process to obtain the inspection data
evaluation and are properly documented After the final rule was published,
and perform the needed inspections.
in the damage-tolerance-based mainte­ Boeing organized and held five model-
■■ A process to conduct surveys of airplanes
nance program. specific Structures Task Group (STG)
to determine whether existing repairs will
meetings to guide development of the
require damage tolerance inspections. Existing repairs. Existing repairs are
Boeing docu­ments that operators would
defined as those installed prior to
use to assist them in the development of

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ae r o q ua r t e r ly   qtr_02 | 10
Figure 1: AASR compliance process
Operators use Boeing documents and their
existing maintenance programs to develop
implementation plans.

Type Certificate Operator

(TC) or
Design Approval
Holder (DAH)
Existing
Program

OIPs OIPs
Revised
Program

Boeing

Compile Plan Review Deliver

Baseline programs New Operator Implementation OIPs are reviewed by the Incorporation of the OIP into
and FAA-Oversight- Plans (OIPs) outline damage Principal Maintenance the Maintenance Program
Office-approved tolerance inspection Inspector (PMI). is approved by the PMI by
Boeing documents. and evaluation processes. December 20, 2010.

their implemen­tation plan. The groups were Information for operators ing damage-tolerance-based maintenance
organized according to AAWG guidelines, provided by Boeing programs for existing repairs to fatigue-
and each STG had representation of critical structure. This document is model
approximately 60 percent of the active Boeing has developed FAA-approved specific and provides requirements for
airplanes in a specific airplane fleet. methods of compliance to support operator the operator to perform surveys and
The compliance process developed compliance. As part of this effort, Boeing establish damage-tolerance-based
by these groups involves operators using is making available both new and updated maintenance programs for existing repairs
Boeing documents and their existing model-specific material to help ensure using the Boeing data listed below. In
maintenance programs to develop operator operator compliance with AASR (see fig. 2). addition, the document estab­lishes
implementation plans. These plans are The model-specific information is currently time periods for a variety of actions to
reviewed and approved by the operator’s available for pur­chase on the Web portal be accomplished, including:
FAA principal maintenance inspector (or MyBoeingFleet.com unless otherwise noted:
■■ Completion of surveys.
local regulatory authority). The plan is then
Compliance document and repair eval­ ■■ Determination of damage tolerance
used as a means by which the damage
uation guidelines. The FAA required inspections.
tolerance data is aggregated and used to
Boeing to make available an FAA-approved ■■ Accomplishment of first inspections.
revise the maintenance program after
compliance document and repair evaluation ■■ Available grace periods.
December 20, 2010 (see fig. 1).
guidelines to assist an operator in estab­lish­

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www.boeing.com/c o m m e r c ia l/ a er o ma g a zi n e
 Figure 2: New and updated publications to assist in operator compliance
Boeing has made these materials available to help airlines operating these models comply with the new
AASR. This table shows the document numbers for the various categories of published data.

Baseline Programs

Model Maintenance Maintenance Supplemental Repair Fatigue Fatigue Critical Structural Repair Fleet Support
Planning Data Planning Data/ Structural Assessment Critical Alteration Structure Manual (SRM) Collector Service
Structures/ Airworthiness Inspection Guidelines Baseline (FCAS) Bulletin (FSSB)
Zonal Limitations Document (RAG) Structure
Programs Instructions (SSID) (FCBS)
(ALI)

Douglas Models

717 ME717-0302 MDC-96K9063 N/A N/A MDC-08K9008 MDC-08K9023-Vol-06 D634L201 717-00-0001

MEDAC-336521 MDC-08K9023-Vol-01 -50/-60: TP-8SRM

DC-8 N/A DM-IS-SID-8-1 MDC-91K0262 MDC-08K9009 DC8-00-001
ME8-00032 MDC-08K9023-Vol-02 -70: TP87SRM

MDC-08K9023-Vol-01
DC-9 ME9-0012 N/A DM-IS-SID-9-1 MDC-08K9010 TP-9SRM DC9-00-001
MDC-08K9023-Vol-03
MDC-91K0263
761-93MSG22 DM-IS-
MD-80 N/A MDC-08K9011 MDC-08K9023-Vol-04 TP-9SRM MD80-00-004
ME80-0203 SID-80-1

MD-90 ME90-0402 MDC-94K9000 N/A N/A MDC-08K9007 MDC-08K9023-Vol-05 TP-90SRM MD90-00-001

-10: TP-10SRM-10
ME10-0081 MDC-08K9023-Vol-01 -30: TP-10SRM-30
DC-10 N/A MDC-08K1002 DC10-00-001
ME10-382 MDC-08K9023-Vol-07 -40: TP-10SRM-40 &
DM-IS- TP-10SRM-4J
MDC-91K0264
SID-10-1
ME10-0171 MDC-08K9023-Vol-01 -10: TP-10MD10SRM-10
MD-10 MDC-99K1082 MDC-08K1003 MD10-00-002
ME10-38-ORS2 MDC-08K9023-Vol-09 -30: TP-10MD10SRM-30

-1F: TP-11SRM-1F
MDC-08K9023-
MD-11 ME11-0152 MDC-K5225 N/A N/A MDC-08K1004 -1P: TP-11SEM-1P MD11-00-003
Vol-08
-CF: TP-11SRM-CF

7-series except 717

727 N/A N/A D6-48040-1 D6-56167 D6-84024 D6-84179 D6-4062 727-00-0015

737-100/-200 N/A N/A D6-37089 D6-15565

D6-38669 D6-84141 -300: D6-37635 737-00-1006

737-300 /
N/A N/A D6-82669 -400: D6-38246
‑400 /‑500
-500: D6-38441

D6-84180 -600: D634A220

-700: D634A201
Next- -700CONV: D634A202
Generation D626A001 D626A001-9 N/A N/A D926A120-01 -700IGW: D634A330 737-00-1007
737 -800: D634D210
-900: D634A211
-900ER: D634A213

747-100 / -100/-200/-300: D6-13592

N/A N/A 747-00-2157
‑200 /‑300 /‑SP -SP: D6-34024
D926U120-01 D624U050-03
D6-841101 D6-841101
-400: D634U102
747-400 N/A N/A
D6-35022 D6-36181 -400F: D634U103
747-00-2157 CL
747-400LCF N/A N/A D926U121-01 D634U105 747-00-2158-400

747-400BCF N/A N/A D926U122-01 D634U104

-200: D634N201
-200PF: D634N210
757 D622N001 D622N001-9 N/A N/A D926N120-01 D190N001 757-00-0003
-200CB: D634N211
-300: D634N230

-200: D634T201
-200SF: D634T202
-300: D634T210
767 D622T001 D622T001-9 N/A N/A D926T120-01 D624T050-02 767-00-0048
-300BCF: D634T235
-300F: D634T215
-400: D634T225

-200: D634W201
777 D622W001 D622W001-9 N/A N/A D926W120-01 D624W050-01 -300: D634W210 777-00-0002
-F: D634W215

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ae r o q ua r t e r ly   qtr_02 | 10
Additional documents unique to Douglas models:
Structural Repair Drawings Damage
Tolerance Summary
DC-8 MDC-09K9014
DC-9, MD-80, MD-90, 717 MDC-09K9015
DC-10, MD-10, MD-11 MDC-09K1012

Master Change Compliance

Fatigue-critical structure. Boeing has made specific configurations. Operators purchase
Collector Service Document and available lists of fatigue-critical baseline struc­ a master-change collector document by
Bulletin (MCSB) Repair Evaluation
Guidelines ture for all affected models. The FAA has submitting a request for proposal to Boeing.)
(CD/REG)
defined fatigue-critical structure as “airplane
Boeing AASR seminar. Boeing is also
structure that is susceptible to fatigue crack­
conducting AASR seminars focusing on the
ing that could contribute to a catastrophic
MDC-09K9009 & steps necessary to establish compliance
717-00-0023
MDC-09K90184 failure. [It] includes structure that, if repaired
with the new operational rules and the
or altered, could be suscep­tible to fatigue
DC8-00-0023
MDC-09K9010 & Boeing publications developed to support
MDC-09K90184 cracking and contribute to a catastrophic
operator compliance. Availability can
MDC-09K9011 & failure. Such structure may be part of the
DC9-00-0023
MDC-09K90184 be found at http://active.boeing.com/
baseline structure or part of an alteration.”
nosearch/svceng/seminars.cfm.
MD80-00-0033
MDC-09K9012 & Operators can use the lists provided by
MDC-09K90184
Boeing to determine whether a repair or an
MDC-09K9013 & alteration requires a damage tolerance eval­ Summary
MD90-00-0023
MDC-09K90184
uation and the development of damage
MDC-09K1009 & tolerance inspections. Boeing has also made A major change to structural maintenance
DC10-00-0033
MDC-09K90184
available lists of fatigue-critical alteration programs for all 7-series, DC, and MD
structure for those master changes and sup­ trans­port category airplanes operated
MDC-09K1010 &
MD10-00-0043 plemental type certificates held by Boeing. under CFR 121 and 129 will be required
MDC-09K90184
on December 20, 2010. The FAA rule
MDC-09K1011 & Published data. Boeing has updated
MD11-00-0043
MDC-09K90184 change requires operators to have
published repair and alteration data for
damage-tolerance-based maintenance
all applicable models to include damage
programs for affected transport category
D6-84300 & tolerance inspections. This includes
727-00-00162 airplanes and requires a physical survey
D6-843403 structural repair manuals, fleet-support
of airplanes to obtain damage tolerance
service bulletins, master-change service
data for repairs and alterations.
737-00-10082
D6-84301 & bulletins, and Boeing-held supplemental
D6-843403 Boeing has published new and updated
type certificates. The damage tolerance
material to help operators comply with
inspections for service bulletins have been
this new rule. All Boeing data needed by
published in a single service bulletin collec­
operators to com­ply with the new rule is
D042A525 & tor document for each airplane model. In
737-00-10092
D6-843403
available for pur­chase on MyBoeingFleet.
the future, when individual service bulletins
com, except for customized master-change
(listed in the service bulletin collector docu­
service bulletins, which are available by
ment) are revised, the damage tolerance
request. Boeing is conducting seminars
inspection information will be included in
on this subject
the new release and the information in the
D926U200-01 & For more information, please contact
747-00-21552
D6-843403
collector document will no longer apply.
Roxanne Pillo at roxanne.m.pillo@
(Collector documents for master-change
boeing.com. 
service bulletins will be generated upon
request and customized to reflect operator-
D042N521 &
757-00-00042
D6-843403 FOOTNOTES: DC, MD and 717
1
On airplane maintenance planning document for use in MSG-2 maintenance programs.
2
Maintenance planning data document for use in MSG-3 maintenance programs.
3
Collector for all master changes. Operators will receive a unique document and document number based on their
D926T242-01 & particular fleet.
767-00-00492
D6-843403 4
Equivalency guidelines referenced in the CD/REG document.

FOOTNOTES: 7-series except 717

1
D6-84110 is the list of alteration service bulletins that affect FCBS and FCAS.
D926W221-01 & 2
Collector for all master changes. Operators will receive a unique document and document number based on their
777-00-00032
D6-843403 particular fleet.
3
Equivalency guidelines referenced in the CD/REG document.

N/A = Not applicable

19