Tag Archives: 56-6670

North American Aviation, Inc., X-15A Hypersonic Research Rocketplane

December 20, 2024Aviation56-6670, 56-6671, 56-6672, Boeing NB-52A Stratofortress, Boeing NB-52B Stratofortress, Edwards Air Force Base, Full-Pressure Suit, Inconel X, NASA X-15 Hypersonic Research Program, North American Aviation Inc., North American Aviation Model NA-240, North American Aviation X-15A, Reaction Motors XLR11-RM-13, Reaction Motors XLR99-RM-1, Rogers Dry LakeBryan Swopes

Rollout AFFTC History Office — North American Aviation, Inc., X-15A-1, 56-6670, at Los Angeles Division, October 1958. (Air Force Flight Test Center History Office)

20 December 1968: After 199 flights, the National Aeronautics and Space Administration cancelled the X-15 Hypersonic Research Program. A 200th X-15 flight had been scheduled, but after several delays, the decision was made to end the program. (The last actual flight attempt was 12 December 1968, but snow at several of the dry lakes used as emergency landing areas resulted in the flight being cancelled.)

The X-15A rocketplane was designed and built for the U.S. Air Force and the National Advisory Committee for Aeronautics (NACA, the predecessor of NASA) by North American Aviation, Inc., to investigate the effects of hypersonic flight (Mach 5+). Design work started in 1955 and a mock-up had been completed after just 12 months. The three X-15s were built at North American’s Los Angeles Division, at the southeast corner of Los Angeles International Airport (LAX), on the shoreline of southern California.

The first flight took place 8 June 1959 with former NACA test pilot Albert Scott Crossfield in the cockpit of the Number 1 ship, 56-6670.

Scott Crossfield prepares for a flight in the North American Aviation X-15A.

While earlier rocketplanes, the Bell X-1 series, the the Douglas D-558-II, and the Bell X-2, were airplanes powered by rocket engines, the X-15 was a quantum leap in technology. It was a spacecraft.

Like the other rocketplanes, the X-15 was designed to be carried aloft by a “mothership,” rather than to takeoff and climb to the test altitude under its own power. The carrier aircraft was originally to be a Convair B-36 intercontinental bomber but this was soon changed to a Boeing B-52 Stratofortress. Two B-52s were modified to carry the X-15: NB-52A 52-003, The High and Mighty One, and NB-52B 52-008, Balls 8.

From 8 June 1959 to 24 October 1968, the three X-15s were flown by twelve test pilots, three of whom would qualify as astronauts in the X-15. Two would go on to the Apollo Program, and one, Neil Alden Armstrong, would be the first human to set foot on the surface of the Moon, 20 July 1969. Joe Engle would fly the space shuttle. Four of the test pilots, Petersen, White, Rushworth, and Knight, flew in combat during the Vietnam War, with Bob White being awarded the Air Force Cross. Petersen, Rushworth and White reached flag rank.

One pilot, John B. (“Jack”) McKay, was seriously injured during an emergency landing at Mud Lake, Nevada, 9 November 1962. Another, Michael James Adams, was killed when the Number 3 ship, 56-6672, went into a hypersonic spin and broke up on the program’s 191st flight, 15 November 1967.

North American Aviation, Inc. X-15A 56-6670 on Rogers Dry Lake, Edwards Air Force Base, California. (NASA) — North American Aviation, Inc., X-15A-1 56-6670 on Rogers Dry Lake, Edwards Air Force Base, California. (NASA Image E-5251)

Flown by a single pilot/astronaut, the X-15 is a mid-wing monoplane with dorsal and ventral fin/rudders and stabilators. The wing had no dihdral, while the stabilators had a pronounced -15° anhedral. The short wings have an area of 200 square feet (18.58 square meters) and a maximum thickness of just 5%. The leading edges are swept to 25.64°. There are two small flaps but no ailerons. The entire vertical fin/rudder pivots for yaw control.

Above 100,000 feet (30,840 meters) altitude, conventional aircraft flight control surfaces are ineffective. The X-15 is equipped with a system of reaction control jets for pitch, roll and yaw control. Hydrogen peroxide was passed through a catalyst to produce steam, which supplied the control thrusters.

The forward landing gear consists of a retractable oleo strut with steerable dual wheels and there are two strut/skids at the rear of the fuselage. The gear is retracted after the X-15 is mounted on the NB-52 and is extended for landing by its own weight.

North American Aviation X-15A 56-6672 touches down on Rogers Dry Lake. (NASA) — North American Aviation, Inc., X-15A-3 56-6672 just before touch down on Rogers Dry Lake. (NASA Image E-7469)

The rocketplane’s cockpit featured both a conventional control stick as well as side-controllers. It was pressurized with nitrogen gas to prevent fires. The pilot wore an MC-2 full-pressure suit manufactured by the David Clark Company of Worcester, Massachusetts, with an MA-3 helmet. The suit was pressurized below the neck seal with nitrogen, while the helmet was supplied with 100% oxygen. This pressure suit was later changed to the Air Force-standardized A/P22S.

X-15A cockpit with original Lear Siegler instrument panel. (NASA) — X-15 cockpit with original Lear Siegler instrument panel. (NASA image E63-9834)

The X-15 is 50.75 feet (15.469 meters) long with a wing span of 22.36 feet (6.815 meters). The height—the distance between the tips of the dorsal and ventral fins—is 13.5 feet (4.115 meters). The stabilator span is 18.08 feet (5.511 meters). The fuselage is 4.67 feet (1.423 meters) deep and has a maximum width of 7.33 feet (2.234 meters).

Since the X-15 was built of steel rather than light-weight aluminum, as are most aircraft, it is a heavy machine, weighing approximately 14,600 pounds (6,623 kilograms) empty and 34,000 pounds (15,422 kilograms) when loaded with a pilot and propellants. The X-15s carried as much as 1,300 pounds (590 kilograms) of research instrumentation, and the equipment varied from flight to flight. The minimum flight weight (for high-speed missions): 31,292 pounds (14,194 kilograms) The maximum weight was 52,117 pounds (23,640 kilograms) at drop (modified X-15A-2 with external propellant tanks).

Initial flights were flown with a 5 foot, 11 inch (1.803 meters)-long air data boom at the nose, but this would later be replaced by the “ball nose” air sensor system. The data boom contained a standard pitot-static system along with angle-of-attack and sideslip vanes. The boom and ball nose were interchangeable.

Neil Armstrong with the first North American Aviation X-15A, 56-6670, on Rogers Dry Lake after a flight, 1960. His hand is resting on the rocketplane's ball nose sensor. (NASA) — NASA Research Test Pilot Neil A. Armstrong with the first North American Aviation X-15A, 56-6670, on Rogers Dry Lake after a flight, 1960. His right hand is resting on the rocketplane’s ball nose sensor. (NASA Image E60-6286)

The X-15s were built primarily of a nickel/chromium/iron alloy named Inconel X, along with corrosion-resistant steel, titanium and aluminum. Inconel X is both very hard and also able to maintain its strength at the very high temperatures the X-15s were subjected to by aerodynamic heating. It was extremely difficult to machine and special fabrication techniques had to be developed.

Delays in the production of the planned Reaction Motors XLR99 rocket engine forced engineers to adapt two vertically-stacked Reaction Motors XLR11-RM-13 four-chamber rocket engines to the X-15 for early flights. This was a well-known engine which was used on the previous rocketplanes. The XLR11 burned a mixture of ethyl alcohol and water with liquid oxygen. Each of the engines’ chambers could be ignited individually. Each engine was rated at 11,800 pounds of thrust (58.49 kilonewtons) at Sea Level.

Two Reaction Motors Division XLR11-RM-5 four-chamber rocket engines installed on an X-15. (NASA) — Two Reaction Motors Division XLR11-RM-13 four-chamber rocket engines installed on an X-15. The speed brakes of the ventral fin are shown in the open position. (NASA)

The Reaction Motors XLR99-RM-1 rocket engine was throttleable by the pilot from 28,500 to 60,000 pounds of thrust (126.77–266.89 kilonewtons). The engine was rated at 50,000 pounds of thrust (222.41 kilonewtons) at Sea Level; 57,000 pounds (253.55 kilonewtons) at 45,000 feet (13,716 meters), the typical drop altitude; and 57,850 pounds (257.33 kilonewtons) of thrust at 100,000 feet (30,480 meters). Individual engines varied slightly. A few produced as much as 61,000 pounds of thrust (271.34 kilonewtons).

The XLR99 burned anhydrous ammonia and liquid oxygen. The flame temperature was approximately 5,000 °F. (2,760 °C.) The engine was cooled with circulating liquid oxygen. To protect the exhaust nozzle, it was flame-sprayed with ceramic coating of zirconium dioxide. The engine is 6 feet, 10 inches (2.083 meters) long and 3 feet, 3.3 inches (0.998 meters) in diameter. It weighs 910 pounds (413 kilograms). The Time Between Overhauls (TBO) is 1 hour of operation, or 100 starts.

Thiokol Reaction Motors Division XLR-RM-1 rocket engine. (U.S. Air Force) — Thiokol Corporation Reaction Motors Division XLR99-RM-1 rocket engine. (U.S. Air Force)

The XLR99 proved to be very reliable. 169 X-15 flights were made using the XLR99. 165 of these had successful engine operation. It started on the first attempt 159 times.

The highest speed achieved during the program was with the modified number two ship, X-15A-2 56-6671, flown by Pete Knight to Mach 6.70 (6,620 feet per second/4,520 miles per hour/7,264 kilometers per hour) at 102,700 feet (31,303 meters). On this flight, the rocketplane exceeded its maximum design speed of 6,600 feet per second (2,012 meters per second).

The maximum altitude was reached by Joe Walker, 22 August 1963, when he flew 56-6672 to 354,200 feet (107,960 meters).

The longest flight was flown by Neil Armstrong, 20 April 1962, with a duration of 12 minutes, 28.7 seconds.

North American Aviation X-15A-1 56-6670 is on display at the Smithsonian Institution National Air and Space Museum. X-15A-2 56-6671 is at the National Museum of the United States Air Force.

A North American Aviation F-100 Super Sabre chase plane follows NB-52A 52-003 prior to launch of an X-15. (NASA)

5 December 1963

December 5, 2024Aviation, Space Flight52-008, 56-6670, Balls 8, Boeing NB-52B Stratofortress, Delamar Dry Lake, Edwards Air Force Base, Flight Test, NASA 670, NASA X-15 Hypersonic Research Program, North American Aviation Inc., North American Aviation X-15A, Reaction Motors XLR99-RM-1, Robert A. Rushworth, Test Pilot, X-15Bryan Swopes

5 December 1963: On Flight 97 of the X-15 Program, Major Robert A. Rushworth flew the number one aircraft, Air Force serial number 56-6670, to an altitude of 101,000 feet 30,785 meters) and reached Mach 6.06 (4,018 miles per hour/6,466 kilometers per hour).

The rocketplane was dropped from the Boeing NB-52B Stratofortress “mother ship” 52-008, Balls 8, flying at 450 knots (833.4 kilometers per hour) at 45,000 feet (13,716 meters) over Delamar Dry Lake, Nevada. Rushworth ignited the Reaction Motors XLR-99-RM-1 rocket engine, which burned for 81.2 seconds before shutting down.

The flight plan had called for an altitude of 104,000 feet (31,699 meters), a 78 second burn and a maximum speed of Mach 5.70. With the difficulties of flying such a powerful rocketplane, Rushworth’s flight was actually fairly close to plan. During the flight the right inner windshield cracked.

Bob Rushworth landed the X-15 on Rogers Dry Lake at Edwards Air Force Base, California, after a flight of 9 minutes, 34.0 seconds.

Mach 6.06 was the highest Mach number reached for an unmodified X-15.

56-6670 flew 81 of the 199 flights of the X-15 Program. It is in the collection of the Smithsonian Institution National Air and Space Museum.

From 1960 to 1966, Bob Rushworth made 34 flights in the three X-15s, more than any other pilot.

North American Aviation Inc./U.S. Air Force/NASA X-15A 56-6670 hypersonic research rocketplane on display at the National Air and Space Museum. (Photo by Eric Long, National Air and Space Museum, Smithsonian Institution)

4 November 1960

November 4, 2024Aviation, Space Flight52-003, 52-008, 56-6670, 56-6671, Balls 8, Boeing NB-52A Stratofortress, Boeing NB-52B Stratofortress, Edwards Air Force Base, Mothership, NASA X-15 Hypersonic Research Program, North American Aviation Inc., North American Aviation X-15A, Robert A. Rushworth, Rocketplane, Test Pilot, The High and the Mighty OneBryan Swopes

At the left, Boeing NB-52A 52-003 carries X-15 56-6670 while on the right, NB-52B 52-008 carries X-15 56-6671.(NASA) — At the left, Boeing NB-52A 52-003 carries X-15 56-6670 while on the right, NB-52B 52-008 carries X-15 56-6671. (NASA)

4 November 1960: This photo shows one of the four attempts NASA made at launching two X-15 aircraft in one day. This attempt occurred November 4, 1960.

None of the four attempts was successful, although one of the two aircraft involved in each attempt usually made a research flight.

In this case, Air Force test pilot Major Robert A. Rushworth flew X-15 #1, 56-6670, on its sixteenth flight to a speed of Mach 1.95 and an altitude of 48,900 feet (14,905 meters).

24 October 1968

October 24, 2024Aviation1, 52-003, 56-6670, Boeing NB-52A Stratofortress, Final Flight, NASA X-15 Hypersonic Research Program, Reaction Motors XLR99-RM-1, William Harvey DanaBryan Swopes

William Harvey Dana, NASA Research Pilot. (National Aeronautics and Space Administration E-5327)

24 October 1968: William Harvey Dana takes the first North America Aviation X-15 hypersonic research rocketplane, 56-6670, for the 199th and final flight of the X-15 program.

Carried aloft by NASA’s Boeing NB-52A Stratofortress mothership, 52-003, the first X-15A was launched over Smith Ranch Dry Lake, about half-way between the city of Reno and the NASA High Range Tracking Station at Ely, Nevada, at 10:02:47.3 a.m., Pacific Daylight Time (17:02:47.3 UTC). Bill Dana started the Reaction Motors XLR99-RM-1 rocket engine for a planned 84 second burn. The flight plan called for the X-15 to reach Mach 5.45 and 250,000 feet (76,200 meters).

The rocketplane’s performance was very close to plan, a tribute to Dana’s piloting skill. The engine burned out after 83.8 seconds. The maximum speed was slightly lower than planned at Mach 5.38, while the peak altitude was a little higher, at 255,000 feet (77,724 meters).

Dana glided back to Edwards Air Force Base. The total duration of the flight was 11 minutes, 28.3 seconds.

Dana made his first flight in the North American Aviation X-15 hypersonic research rocketplane on 4 November 1965. He reached a maximum speed of Mach 4.22, and a peak altitude of 80,200 feet (24,445 meters). He made a total of sixteen flights in the X-15s. Dana’s highest speed was Mach 5.38, and his highest altitude, 306,900 feet, (93,543 meters), on 1 November 1966.

This had been 56-6670’s 81st flight, and the 141st time it had been carried aloft aboard a B-52.

A. Scott Crossfield, wearing a David Clark Co. XMC-2 full-pressure suit, which he helped to design and test, with the first of three North American X-15s, 56-6670. (North American Aviation, Inc.)

56-6670 is the first of three X-15s built by North American Aviation’s Los Angeles Division for NASA, the United States Air Force, and the United States Navy, to investigate the effects of hypersonic flight (Mach 5+). On 8 June 1959, North American Aviation Chief Engineering Test Pilot, and former NACA research test pilot, Albert Scott Crossfield, had made the first glide flight of 56-6670, also launched by 52-003.

NASA Research Pilot William H. Dana with North American X-15A 56-6672 on Rogers Dry Lake. (NASA)

Overhead view of X-15A-1 56-6670 shows the rocketplane’s overall fineness ratio and short wings. (North American Aviation, Inc.)

Flown by a single pilot/astronaut, the X-15 is a mid-wing monoplane with dorsal and ventral fin/rudders and stabilators. The wing had no dihedral, while the stabilators had a pronounced 15° anhedral. The short wings have an area of 200 square feet (18.58 square meters) and a maximum thickness of just 5%. The leading edges are swept to 25.64°. There are two small flaps but no ailerons. The entire vertical fin pivots for yaw control.

X-15 56-6670 with NB-52A 52-003, 13 April 1960. (NASA)

Since the X-15 was built of steel rather than light-weight aluminum, as are most aircraft, it is a heavy machine, weighing approximately 14,600 pounds (6,623 kilograms) empty and 34,000 pounds (15,422 kilograms) when loaded with a pilot and propellants. The X-15s carried as much as 1,300 pounds (590 kilograms) of research instrumentation, and the equipment varied from flight to flight. The minimum flight weight (for high-speed missions): was 31,292 pounds (14,194 kilograms) The maximum weight was 52,117 pounds (23,640 kilograms) at drop (modified X-15A-2 with external propellant tanks).

Delays in the production of the planned Reaction Motors XLR99 rocket engine forced engineers to adapt two vertically-stacked Reaction Motors XLR11-RM-5 four-chamber rocket engines to the X-15 for early flights. This was a well-known engine which was used on the previous rocketplanes. The XLR11 burned a mixture of ethyl alcohol and water with liquid oxygen. Each of the engines’ four chambers could be ignited individually. Each engine was rated at 11,800 pounds of thrust (58.49 kilonewtons) at Sea Level.

Thiokol Reaction Motors Division XLR99-RM-1 rocket engine. (U.S. Air Force)

The Reaction Motors XLR99-RM-1 rocket engine was throttleable by the pilot from 28,500 to 60,000 pounds of thrust. The engine was rated at 50,000 pounds of thrust (222.41 kilonewtons) at Sea Level; 57,000 pounds (253.55 kilonewtons) at 45,000 feet (13,716 meters), the typical drop altitude; and 57,850 pounds (257.33 kilonewtons) of thrust at 100,000 feet (30,480 meters). Individual engines varied slightly. A few produced as much as 61,000 pounds of thrust (271.34 kilonewtons).

The XLR99 proved to be very reliable. 169 X-15 flights were made using the XLR99. 165 of these had successful engine operation. It started on the first attempt 159 times.

The highest speed achieved during the program was with the modified number two ship, X-15A-2 56-6671, flown by Pete Knight to Mach 6.70 (6,620 feet per second/4,520 miles per hour/ kilometers per hour) at 102,700 feet (31,303 meters). On this flight, the rocketplane exceeded its maximum design speed of 6,600 feet per second (2,012 meters per second).

The maximum altitude was reached by Joe Walker, 22 August 1963, when he flew 56-6672 to 354,200 feet (107,960 meters).

The longest flight was flown by Neil Armstrong, 20 April 1962, with a duration of 12 minutes, 28.7 seconds.

The North American Aviation, Inc., X-15A-1, 56-6670, being brought into the Arts and Industries building, June 1969. (Smithsonian Institution Archives SI-A-4145-23-A)

North American Aviation X-15A-1 56-6670 is on display at the Smithsonian Institution National Air and Space Museum. X-15A-2 56-6671 is at the National Museum of the United States Air Force.

North American Aviation Inc./U.S. Air Force/NASA X-15A 56-6670, hypersonic research rocketplane on display at the National Air and Space Museum. (NASM)

Albert Scott Crossfield, Jr. (2 October 1921–19 April 2006)

October 2, 2024Aviation56-6670, A. Scott Crossfield, Aeronautical Engineer, Albert Scott Crossfield, Bell X-1, Cessna 210A Centurion, Collier Trophy, Douglas D-558-II Skyrocket, Edwards Air Force Base, Fighter Pilot, Harmon Trophy, High Speed Flight Station, Hypersonic, N6579X, NACA, NASA, NASA X-15 Hypersonic Research Program, National Advisory Committee for Aeronautics, National Aeronautics and Space Administration, Naval Aviator, North American Aviation X-15A, Rocketplane, Scott Crossfield, Scotty Crossfield, Test PilotBryan Swopes

Albert Scott Crossfield, aeronautical engineer and test pilot, 1921–2006. (Jet Pilot Overseas) — Albert Scott Crossfield, Jr., Aeronautical Engineer and Test Pilot, 1921–2006. (Jet Pilot Overseas)

Albert Scott Crossfield, Jr., was born at Berkeley, California, 2 October 1921, the second of three children of Albert Scott Crossfield and Lucia Dwyer Scott Crossfield. (“Scott Crossfield” is the family name, going back for many generations.) His father was a chemist who was the superintendent of the Union Oil Refinery in Wilmington, California. At the age of 5 years, the younger Scott Crossfield contracted pneumonia. He was comatose for a time and not expected to survive. When he finally began to recover, he was confined to bed for many months. The effects of this illness lasted throughout his childhood.

It was during this time that he developed his interest in aviation. He learned to draw, studied airplanes, and built scale models. Charles F. (“Carl”) Lienesch, who was a pilot for the Union Oil Company, gave Scotty his first ride aboard an airplane at age 6. As a teenager, he took flight lessons in an Inland Sportster at the Wilmington Airport.

Inland R400 Sportster NC267N, circa 1939. (William T. Larkins)

After his family bought a farm in Oregon, Scott Crossfield continued flight lessons and soloed a Curtis Robin at the age of 15. He earned his private pilot certificate at 18. After graduating from high school, “Scotty” helped his father with the family farm before attending the University of Washington as a student of aeronautical engineering. He took a job at Boeing to pay his tuition and support.

After America’s entry into World War II, Scott Crossfield enlisted in the U.S. Army Air Corps as an aviation cadet, but because of expected delays in training, quickly transferred to the U.S. Navy. He enlisted as a Seaman 2/c in the Navy’s V-5 Program at the Naval Reserve Aviation Base, Seattle, Washington, on 21 February 1942. He began Primary Flight Training there, 7 May 1942. Scotty completed military flight training and was commissioned an Ensign, United States Navy, in December 1942.

On 21 April 1943, Ensign Albert Scott Crossfield, U.S. Navy, married Miss Alice Virginia Knoph at Corpus Christi, Texas.

Promoted to lieutenant (junior grade) with date of precedence 21 March 1944.

During World War II, Scott Crossfield served as a fighter pilot, flight and gunnery instructor, flying the Chance Vought F4U Corsair and Grumman F6F Hellcat. Though he was assigned to Fighting Squadron FIFTY-ONE (VF-51) aboard the Independence-class light aircraft carrier USS Langley (CVL-27), he did not serve in combat. He was promoted to the rank of lieutenant 1 August 1945. Scotty was released from active duty 31 December 1945. After the war he joined a Naval Reserve squadron and flew the Goodyear Aircraft Co. FG-1D Corsair at NAS Sand Point, Washington.

A Goodyear FG-1D Corsair, Bu. No. 92150, unfolding its wings at NAS Sand Point, circa late 1940s. The orange band around the fuselage shows that this airplane is assigned to a Naval Reserve squadron. (U.S. Navy)

During this time he resumed his education at the University of Washington and graduated with a bachelor’s degree in aeronautical engineering in 1949, and a master’s degree in 1950. As a graduate student he was the operator of the university’s Kirsten Aeronautical Laboratory wind tunnel.

The NACA High Speed Flight Station, 24 August 1954. The Boeing P2B-1S Superfortress is parked at the northeast corner of the ramp. (NASA)

In 1950 Scott Crossfield joined the National Advisory Committee for Aeronautics (NACA, the predecessor of NASA) as an Aeronautical Research Pilot at the NACA High Speed Flight Station, Edwards Air Force Base, California. He flew many high-performance jet aircraft like the North American Aviation F-100 Super Sabre, and experimental airplanes such as the Convair XF-92, Douglas X-3, Bell X-4 and X-5. He also flew the research rocket planes, making 10 rocket flights in the Bell X-1 and 77 in the Douglas D-558-II Skyrocket.

Douglas D-558-2 Bu. No. 37974 dropped from Boeing P2B-S1 Superfortress 84029, 1 January 1956. (NASA) — Douglas D-558-2 Skyrocket, Bu. No. 37974, is dropped from Boeing P2B-S1 Superfortress, Bu. No. 84029, 1 January 1956. (NASA)

On 20 November 1953, Scott Crossfield became the first pilot to fly faster than twice the speed of sound (Mach 2). The D-558-II was carried aloft by a Boeing P2B-1S Superfortress drop ship (a four-engine B-29 long range heavy bomber which had been transferred from the U.S. Air Force to the Navy, then heavily modified by Douglas) to 32,000 feet (9,754 meters) and then released. Scotty fired the LR8 rocket engine and climbed to 72,000 feet (21,945 meters). He put the Skyrocket into a shallow dive and, still accelerating, passed Mach 2 at 62,000 feet (18,898 meters). After the rocket engine’s fuel was expended, he flew the rocketplane to a glide landing on Rogers Dry Lake.

In 1955 Crossfield left NACA and joined North American Aviation, Inc., as Chief Engineering Test Pilot. He planned and participated in the design and operation of the X-15 hypersonic research rocketplane for the Air Force and NASA. He also worked closely with the David Clark Co., in the development of the project’s full-pressure suits.

Scott Crossfield testing an experimental David Clark Co. XMC-2 full-pressure suit in a thermal chamber at Wright Field. (Ralph Morse, LIFE Magazine/National Archives College Park Collection)

Milton O. Thompson, another X-15 test pilot, wrote in At the Edge of Space,

“. . . he was intimately involved in the design of the aircraft and contributed immensely to the success of the design, as a result of his extensive rocket airplane experience. . . Scott was responsible for a number of other excellent operational and safety features built into the aircraft. Thus, one might give Scott credit for much of the success of the flight program. . . .”

—At the Edge of Space, by Milton O. Thompson, Smithsonian Institution Press, Washington and New York, 1992, at Page 3

Scott Crossfield, NAA Chief Engineering Test Pilot; Edmond Ross Cokeley, NAA Director of Flight Test; and Charles H. Feltz, NAA Chief Engineer, with an X-15 hypersonic research rocketplane. (North American Aviation via Jet Pilot Overseas)

In 1959–1960, Scott Crossfield flew all of the contractor’s demonstration phase flights for the X-15, including 16 captive carry flights under the wing of the NB-52A Stratofortress while systems were tested and evaluated, one glide flight, and thirteen powered flights. He reached a a maximum altitude of 88,116 feet (26,858 meters) on Flight 6, and a maximum speed of Mach 2.97 (1,960 miles per hour/3,154 kilometers per hour) on Flight 26. The X-15 was then turned over to NASA and the Air Force. The X-15 Program involved a total of 199 flights from 1959 until 1968.

After leaving the X-15 Program, Scott Crossfield continued as a Systems Director with North American Aviation, Inc., working on the Apollo Command and Service Module and the S-IVB second stage of the Saturn V rocket. He left North American in the late ’60s and served as an executive with Eastern Air Lines and Hawker Siddeley. He also continued as a aeronautical engineering consultant to private industry and government.

Among many other awards, Scott Crossfield was received the Harmon Trophy, the Collier Trophy, and the Iven C. Kincheloe Award of the Society of Experimental Test Pilots..

Scott Crossfield's 1962 Cessna 210A Centurion, photographed at Santa Monica Airport, California, 26 September 1999. (AirNikon Collection, Pima Air & Space Museum, Tucson, Arizona via airliners.net) — Scott Crossfield’s Cessna 210A Centurion, N6579X, photographed at Santa Monica Airport, California, 26 September 1999. (AirNikon Collection, Pima Air & Space Museum, Tucson, Arizona via airliners.net, used with permission)

In 1980 Crossfield resumed flying when he purchased a 1960 Cessna 210A Centurion, N6579X, serial number 21057579. This was a single-engine, four-place light airplane, powered by an air-cooled Continental six-cylinder engine. He had flown more than 2,000 hours in this airplane when it crashed during a severe thunderstorm, 19 April 2006, while on a flight from Prattville, Alabama, to Manassas, Virginia.

Albert Scott Crossfield, Jr., was killed. His remains are interred at the Arlington National Cemetery, Arlington, Virginia.

Albert Scott Crossfield, Jr., Test Pilot. (LIFE Magazine via Jet Pilot Overseas)

Highly recommended: Always Another Dawn: The Story Of A Rocket Test Pilot, by Albert Scott Crossfield and Clay Blair, Jr., The World Publishing Company, Cleveland and New York, 1960.

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