Tag Archives: Aircraft Accident

17 November 1954

Fairey Aviation Co., Ltd., Delta 2 WG774. (Unattributed)
Fairey Aviation Co., Ltd., Delta 2 WG774. (Wikipedia)
Lieutenant-Commander Lionel Peter Twiss, OBE, DSC and Bar. (The Telegraph)
Lieutenant-Commander Lionel Peter Twiss, O.B.E., D.S.C. and Bar. (The Telegraph)

17 November 1954: Lionel Peter Twiss, Chief Test Pilot for Fairey Aviation Company Ltd., was flying the company’s experimental supersonic airplane, the Fairey Delta 2, WG774, from the aircraft test center at RAF Boscombe Down, Salisbury, Wiltshire, England. This was the FD.2’s fourteenth flight.

When about 30 miles (48 kilometers) from the airfield and climbing through 30,000 feet (9,144 meters), the airplane’s fuel supply was interrupted and the engine flamed out.

Unwilling to lose a valuable research aircraft, Twiss decided to stay with the Delta 2 rather than ejecting, and he glided back to Boscombe Down, descending through a layer of cloud at 2,500 feet (762 meters). Without the engine running, the aircraft had insufficient hydraulic pressure to completely lower the landing gear and only the nosewheel strut locked in place. The FD.2 touched down at 170 miles per hour (274 kilometers per hour) and was seriously damaged.

WG774 was out of service for nearly a year. The wings had to be replaced and those which had originally been built for structural tests were used.

Damaged Fairey Delta 2 WG774 at Boscombe Down. (Prototypes.com)

For his effort to save a valuable research aircraft, Peter Twiss was awarded the Queen’s Commendation for Valuable Service in the Air. Notice of the award was published in The London Gazette, 22 February 1955, at Page 1094:

Lionel Peter Twiss, Test Pilot, Fairey Aviation Company Ltd. (Hillingdon, Middlesex.)

     For services when an aircraft, undergoing tests, sustained damage in the air.

Her Majesty and Prince Phillip look over the Fairey Delta 2 with Lieutenant-Commander Peter Twiss.
Her Majesty and Prince Phillip look over a Fairey Delta 2 with Lieutenant-Commander Peter Twiss in 1956. (Daily Mail)

On 10 March 1956, Peter Twiss flew WG774 to set a Fédération Aéronautique Internationale (FAI) World Record for Speed Over a 15km/25km Straight Course at an average speed over a 9-mile course, flown between Chichester and Portsmouth at and altitude of 38,000 feet (11,582 meters). Two runs over the course were made, with first averaging 1,117 miles per hour (1,798 kilometers per hour) and the second, in the opposite direction, was 1,147 miles per hour. (1,846 kilometers per hour). The FD.2 had averaged 1,822 Kilometers per hour (1,132 miles per hour)—Mach 1.731. ¹

Twiss had broken the previous record of 1,323.312 kilometers per hour (822.268 miles per hour) which had been set by Colonel Horace A. Hanes, U.S.Air Force, flying a North American Aviation F-100C Super Sabre over Edwards Air Force Base, California. ²

Test Pilot Peter Twist shakes hands with Robert L. Lickey, designer of the Fairey Delta 2. (The New York Times)
Test Pilot Lieutenant-Commander Lionel Peter Twiss, D.S.C. and Bar, shakes hands with Robert Lang Lickley, Chief Engineer of Fairey Aviation Co., Ltd., and designer of the Fairey Delta 2. (The New York Times)

Peter Twiss was the first British pilot, and the FD.2 the first British airplane, to exceed 1,000 miles per hour (1,609 kilometers per hour) in level flight. Twiss is also the last British pilot to have held a World Absolute Speed Record.

For his services as a test pilot, Lieutenant-Commander Lionel Peter Twiss, D.F.C. and Bar, was appointed Officer of the Most Excellent Order of the British Empire, 13 June 1957.

Fairey Delta 2 (FD.2) WG774. (Unattributed)
Fairey Delta 2 (FD.2) WG774, 13 March 1956. (Unattributed)

The Fairey Aviation Company, Ltd., Delta 2 WG774 (c/n F9421) is the first of two single-place, single-engine delta-wing research aircraft which had been designed and built to investigate transonic and supersonic speeds. It first flew 6 October 1953 with Chief Test Pilot Peter Twiss in the cockpit.

In its original configuration, the FD.2 is 51 feet, 7½ inches (15.735 meters) long with a wingspan of 26 feet, 10 inches (8.179 meters) and overall height of 11 feet (3.353 meters). The wings’ leading edge were swept to 59.9° with an angle of incidence of +1.5°. Ailerons and flaps were at the trailing edge and acted in place of elevators. In its original configuration it had an empty weight of approximately 11,000 pounds (4,990 kilograms) and the all-up weight at takeoff was 14,109 pounds (6,400 kilograms).

The FD.2 was powered by a Rolls-Royce Avon RA.28R afterburning turbojet engine which produced 9,530 pounds of thrust (42.392 kilonewtons), or 11,820 pounds (52.578 kilonewtons) with afterburner (“reheat”). This was a single-shaft axial-flow turbojet with a 15-stage compressor and 2-stage turbine. The RA.28 was 10 feet, 3.0 inches (3.124 meters) long, 3 feet, 5.5 inches (1.054 meters) in diameter, and weighed 2,869 pounds (1,301 kilograms).

WG774 and its sistership, WG777, were used for flight testing throughout the 1960s. WG774 was modified as a test aircraft to study various features of the planned British Aerospace Concorde. The landing gear struts were lengthened and the fuselage extended by six feet. It received a “drooped” nose section for improved pilot visibility during takeoff and landings. New wings were installed which had an ogee-curved leading edge. With these modifications WG774 was redesignated BAC 221. In this configuration, WG774 was tested to Mach 1.65 at 40,000 feet (12,192 meters).

WG774 was retired in the early 1970s. It is on display at the Fleet Air Arm Museum, Yeovilton, Somerset, England.

Fairey Aviation FD.2 WG7774. (Unattributed)
Fairey Aviation FD.2 WG774, 2 September 1955. (Unattributed)

Peter Lionel Winterton Twiss ³ was born 23 July 1921 at Lindfield, Sussex, England. He was the son of Colonel Dudley Cyril Twiss, M.C., a British Army officer, and Laura Georgina Chapman Twiss. Peter was educated at the Sherborne School, a prestigious boarding school for boys, in Dorset.

Midshipman Lionel Peter Twiss, Royal Navy Volunteer Reserve.

Twiss briefly worked as a tea taster for Brooke Bond & Company, but in 1939 enlisted as a Naval Airman, 2nd class, Royal Navy Volunteer Reserve. He trained at HMS St Vincent, a training school for the Fleet Air Arm at Gosport, Hampshire. He was appointed a Temporary Mishipman (Probationary), 26 August 1940. He was assigned to 771 Squadron, 27 January 1941, and was trained as a fighter pilot. Midshipman Twiss was commissioned as a Temporary Sub-Lieutenant (A), 23 July 1942.

Twiss was variously assigned to HMS Sparrowhawk, a Naval Air Station in the Orkney Islands, where he flew target tugs for gunnery training; HMS Daedalus, at Lee-on-Solent, Hampshire, England; and HMS Saker, a Royal Navy accounting base located in the United States.

Temporary Sub-Lieutenant (A) Lionel Peter Twiss, R.N.V.R., was assigned as the pilot of a Hawker Hurricane Mk.I with the Merchant Ship Fighter Unit. (Hurricanes could be launched by catapult from merchant ships to defend against Luftwaffe Focke-Wulf Fw 200 Condor reconnaissance bombers.)

A Hawker Hurricane Mk.IA, NJ L, mounted on a merchant ship’s catapult. (Lt. J.A. Hampton, RAF) © IWM (A 9421)

He next flew the Fairey Fulmar fighter with No. 807 Squadron from HMS Argus (I49), in support of Malta in the Mediterranean Sea. Sub-Lieutenant Twiss is credited with shooting down one enemy fighter and damaging a bomber. He was awarded the Distinguished Service Cross, 22 September 1942. He and his squadron transitioned to the Supermarine Seafire aboard HMS Furious (47) and were in action during the invasion of North Africa. He was awarded a Bar, denoting a second award, to his D.S.C., 16 March 1943.

Sub-Lieutenant Twiss, D.S.C. and Bar, was promoted to the rank of Temporary Lieutenant, 17 August 1943. After returning to England, Twiss was trained as a night fighter pilot. He flew the de Havilland DH.98 Mosquito with an RAF night fighter unit on intruder missions over France. In 1944 he shot down two more enemy airplanes.

Mosquito Mk.VI night intruder, 1944. © IWM (HU 107770)

Later in 1944, Twiss was sent to the United States to work with the British Air Commission. In this position, he was able to fly various U.S. fighter aircraft, including the turbojet-powered Bell P-59 Airacomet.

Lieutenant-Commander Twiss was in the third class of the Empire Test Pilots’ School and after graduation he was assigned to Fairey Aviation for duty as a test pilot.

With the end of World War II, Lieutenant-Commander Twiss left the Royal Navy and continued working as a civilian test pilot at Fairey. He became to the company’s chief test pilot in 1954.

Peter Twiss with a scale model of the Fairey Delta 2. (The Scotsman)

For his record-setting flight, in 1956 Twiss was awarded The Segrave Trophy of the Royal Automobile Club.

Lionel Peter Twiss,O.B.E., D.S.C. and Bar, at Buckingham Palace, 1957, following his investiture. He is accompanied by his step-daughter, Gillian, and his second wife, Vera Maguire Twiss.

In the Queen’s Birthday Honours, 13 June 1957, Lionel Peter Twiss, Esq., D.S.C., Chief Test Pilot, Fairey Aviation Company, Ltd.,, was appointed an Ordinary Officer of the Civil Division of the Most Excellent Order of the British Empire (O.B.E.). His investiture took place at Buckingham Palace.

In 1958, The Royal Aeronautical Society awarded its George Taylor Gold Medal to Peter Twiss.

Peter Twiss ended his career testing aircraft in 1959, having flown more than 4,500 hours in nearly 150 different aircraft. His autobiography, Faster than the Sun, was published by Macdonald, London, in 1963.

He later worked for Fairey Marine.

Peter Twiss drove the villain Morzeny’s speed boat in “From Russia With Love.”

Twiss made a brief appearance in the 1960 20th Century Fox motion picture, “Sink the Bismarck!” He portrayed the pilot of a Fairey Swordfish torpedo bomber which attacked the enemy battleship. In 1963, Peter Twiss appeared in the Eon Productions James Bond movie, “From Russia With Love.” He piloted one of the SPECTRE speedboats, which were chasing Bond and Tatiana Romanova.

Peter Twiss was married five times. His first wife was Constance A. Tomkinson.⁴ The marriage ended in divorce.

In the summer of 1950, Twiss married Vera Maguire at Wycombe, Buckinghamshire. They would have a daughter, Sarah. Their marriage also ended in divorce.

Mrs. Twiss III (Photographed by Mary Evans)

In June 1960, Twiss married Miss Cherry Felicity Huggins, a fashion model, actress, fashion magazine editor, pilot and race car driver, at Westminster, Middlesex, Their daughter Miranda was born in 1961. For a third time, Twiss’s marriage ended with a divorce. (Mrs. Twiss III would later marry Lord Charles Hambro, and become Lady Hambro.)

Twiss married his fourth wife, Mrs. Heather Danby (née Heather Linda Goldingham) at Gosport, Hampshire, on 4 November 1964. Mrs. Twiss IV died in 1988.

Finally, in December 2002, Peter Twiss married Jane M. de Lucey. They remained together until his death.

Lieutenant-Commander Lionel Peter Twiss, O.B.E., D.F.C. and Bar, died 31 August 2011 at the age of 90 years.

Lionel Peter Twiss, February 2002. (Dan Patterson/National Portrait Gallery NPG x126203)

¹ FAI Record File Number 8866

² FAI Record File Number 8867

³ England and Wales, Civil Registration Birth Index, July, August and September 1921, at Page 868. Birth registered as “Twiss, Peter L. W.” Mother’s maiden name, “Chapman.”

⁴ A marriage license was issued to Lionel P. Twiss and Constance A. Tomkinson in New York City, New York, U.S.A., 24 October 1944.

© 2018, Bryan R. Swopes

15 November 1967

Major Michael J. Adams, United States Air Force, with an X-15 hypersonic research rocketplane on Rogers Dry Lake. (NASA)
Major Michael J. Adams, United States Air Force, with a North American Aviation X-15 hypersonic research rocketplane, 56-6670, on Rogers Dry Lake, after his third flight in the program, 22 March 1967. (NASA)

15 November 1967: Major Michael James Adams, United States Air Force, was killed in the crash of the number three North American Aviation X-15 hypersonic research rocketplane, 56-6672.

Flight 191 of the X-15 program was Mike Adams’ seventh flight in the rocketplane. It was the 56-6672’s 65th flight. The flight plan called for 79 seconds of engine burn, accelerating the X-15 to Mach 5.10 while climbing to 250,000 feet (76,200 meters). Adams’ wife, Freida, and his mother, Georgia Adams, were visiting in the NASA control room at Edwards Air Force Base.

Balls 8, the Boeing NB-52B Stratofortress, 52-008, flown by Colonel Joe Cotton, took off from Edwards at 9:12 a.m., carrying -672 on a pylon under its right wing, and headed north toward the drop point over Delamar Dry Lake in Nevada. The drop ship climbed to the launch altitude of 45,000 feet (13,716 meters).

The X-15 launch was delayed while waiting for the Lockheed C-130 Hercules rescue aircraft to arrive on station. This required Adams to reset the Honeywell MH-96 Automatic Flight Control System to compensate for the changing position of the sun in the sky.

X-15A-3
North American Aviation X-15A-3 56-6672 immediately after launch over Delamar Lake, Nevada. Date unknown. (U.S. Air Force)

56-6672 was launched by Balls 8 at 10:30:07.4 a.m., Pacific Standard Time. As it dropped clear of the bomber, the rocketplane rolled 20° to the right, a normal reaction. Within one second, Mike Adams had started the XLR99-RM-1 rocket engine while bringing the wings level. The engine ignited within one-half second and was up to its full 57,000 pounds of thrust (253.549 kilonewtons) one second later. The engine ran for 82.3 seconds, 3.3 seconds longer than planned, causing the X-15 to reach Mach 5.20 (3,617 miles per hour/5,821 kilometers per hour) and to overshoot the planned altitude to peak at 266,000 feet (81,077 meters).

A North American Aviation X-15 hypersonic research rocketplane leaves a contrail as it climbs toward the edge of space. (NASA)
A North American Aviation X-15 hypersonic research rocketplane leaves a contrail as it climbs toward the edge of space. (NASA)

With the X-15 climbing through 140,000 feet (42,672 meters), the Inertial Flight Data System computer malfunctioned. Adams radioed ground controllers that the system’s malfunction lights had come on.

The flight plan called for a wing-rocking maneuver at peak altitude so that a camera on board could scan from horizon to horizon. During this maneuver, the Reaction Control System thrusters did not respond properly to Adams’ control inputs. The X-15 began to yaw to the right.

As it reached its peak altitude, 56-6672 yawed 15° to the left. Going over the top, the nose yawed right, then went to the left again. By the time the aircraft had descended to 230,000 feet (70,104 meters), it had pitched 40° nose up and yawed 90° to the right its flight path. The X-15 was also rolling at 20° per second. The rocketplane went into a spin at Mach 5.

10:33:37 Chase 1: “Dampers still on, Mike?”

10:33:39 Adams: “Yeah, and it seems squirrelly.”

10:34:02 Adams: “I’m in a spin, Pete.” [Major William J. “Pete” Knight, another X-15 pilot, was the flight controller, NASA 1]

10:34:05 NASA 1: “Let’s get your experiment in and the cameras on.”

10:34:13 NASA 1: “Let’s watch your theta, Mike.”

10:34:16 Adams: “I’m in a spin.”

10:34:18 NASA 1: “Say again.”

10:34:19 Adams: “I’m in a spin.”

Adams fought to recover, and at 118,000 feet (35,967 meters) came out of the spin, but he was in an inverted 45° dive at Mach 4.7. The X-15’s MH-96 Automatic Flight Control System entered a series of diverging oscillations in the pitch and roll axes, with accelerations up to 15 gs. Dynamic pressures on the airframe rapidly increased from 200 pounds per square foot (9.576 kilopascals) to 1,300 pounds per square foot (62.244 kilopascals).

At 62,000 feet (18,898 meters), still at Mach 3.93, the aircraft structure failed and it broke apart.

10:34:59 X-15 telemetry failed. Last data indicated it was oscillating +/- 13 g. Radar altitude was 62,000 feet (18,898 meters). The aircraft was descending at 2,500 feet per second (762 meters per second) and broke into many pieces at this time.

10:35:42 NASA 1: “Chase 4, do you have anything on him?”

10:35:44 Chase 4: “Chase 4, negative.”

10:35:47 NASA 1: “OK, Mike, do you read?”

10:35:52 Chase 4: “Pete, I got dust on the lake down there.”

North American Aviation X-15A-3 56-6672 crashed in a remote area, approximately 5½ miles (9 kilometers) north-northeast of Randsburg, California, a small village along U.S. Highway 395.

Major Michael James Adams was killed. This was the only pilot fatality of the entire 199-flight X-15 program.

North American Aviation X-15A 56-6672 on Rogers Dry Lake after a flight. (NASA)
North American Aviation X-15A-3 56-6672 on Rogers Dry Lake. (NASA)

An investigation by NASA’s Engineering and Safety Center determined that,

“. . . the root cause of the accident was an electrical disturbance originating from an experiment package using a commercial-off-the-shelf (COTS) component that had not been properly qualified for the X-15 environment. . .” and that there is “. . . no conclusive evidence to support the hypothesis that SD [spatial disorientation] was a causal factor. On the contrary, the evidence suggests that poor design of the pilot-aircraft interface and ineffective operational procedures prevented the pilot and ground control from recognizing and isolating the numerous failures before the aircraft’s departure from controlled flight was inevitable.”

A Comprehensive Analysis of the X-15 Flight 3-65 Accident, NASA/TM—2014-218538 (Corrected Copy)

Crushed forward fuseleage of X-15 56-6672. (NASA)
Crushed forward fuselage of North American Aviation X-15A-3 56-6672. (NASA)

Michael James Adams was born at Sacramento, California, 5 May 1930. He was the first of two sons of Michael Louis Adams, a telephone company technician, and Georgia E. Domingos Adams.

Michael Adams throws a javelin at Sacramento J.C. (1949 Pioneer)

After high school, Mike Adams attended Sacramento Junior College, graduating in 1949. He was an outfielder for the college baseball team, and threw the javelin in track & field.

Adams enlisted in the United States Air Force in 1950. He completed basic training at Lackland Air Force Base, San Antonio, Texas. In  October 1951, he was selected as an aviation cadet and sent to Spence Air Force Base, near Moultrie, Georgia, for primary flight training. Cadet Adams completed flight training at Webb Air Force Base, Big Spring, Texas. He graduated 25 October 1952. Adams was one of two distinguished graduates in his class and received a commission as an officer in the regular Air Force.

Second Lieutenant Adams was assigned to advanced flight training at Nellis Air Force Base, where he flew the Lockheed F-80 Shooting Star and North American Aviation F-86 Sabre.

In April 1953, Lieutenant Adams joined the 80th Fighter-Bomber Squadron at K-13, Suwon, Republic of Korea. He flew 49 combat missions.

Mr. and Mrs. Michael J. Adams, 15 January 1955. (Freida Adams Collection)

Following the Korean War, Lieutenant Adams was assigned to the 613th Fighter Bomber Squadron, 401st Fighter-Bomber Group, at England Air Force Base, Alexandria, Louisiana. The Squadron initially flew the F-86F Sabre and then transitioned to the Republic F-84F Thunderstreak. Adams deployed to Chaumont Air Base, France, for a six-month temporary assignment.

While stationed at England AFB, Lieutenant Adams met Miss Freida Beard. They were married in a ceremony at the Homewood Baptist Church in Alexandria, 15 January 1955. They would have three children, Michael James, Jr., Brent, and Liese Faye Adams.

Michael J. Adams, 1958

In 1958, Adams graduated from the University of Oklahoma at Norman, with a bachelor’s degree in aeronautical engineering. He was a member of the university’s Institute of Aeronautical Sciences. Adams was next assigned to the Massachusetts Institute of Technology, Cambridge, Massachusetts, where he studied astronautics.

Adams’ next military assignment was as a maintenance officer course instructor at Chanute Air Force Base, Rantoul, Illinois.

In 1962, Captain Adams entered an eight-month training program at the Air Force Test Pilot School, Class 62C, at Edwards Air Force Base in the high desert of southern California. He was awarded the A.B. Honts Trophy as the class’s outstanding graduate.

Captain Michael J. Adams with a Northrop F-5A. (NASA)

On 17 June 1963, Captain Adams entered the Aerospace Research Pilots School, which was also at Edwards. This was a seven-month course that taught flying skills in advanced vehicles, with an aim to prepare the graduates for space flight, and to create a pool of qualified military test pilots to be selected as astronauts. The Air Force estimated a need for 20 pilots a year for the upcoming X-20 Dyna-Soar and Manned Orbiting Laboratory (M.O.L.) programs. Adams graduated with the second of the four ARPS classes.

Adams then became an operational test pilot, conducting stability and control tests for the Northrop F-5A Freedom Fighter. That was followed by an assignment as a project pilot for the Cornell Aeronautical Laboratory.

On 13 November 1963, it was announced that Michael Adams was on of the selectees for the M.O.L. program. As a designated Air Force astronaut, Adams was involved in lunar landing simulations during the development of the Apollo Program lunar lander.

Artists conception of the U.S. Air Force Manned Orbiting Laboratory (M.O.L.)

Major Adams was selected as a pilot of the NASA/Air Force X-15 Hypersonic Research Flight Program. (He was the twelfth and final pilot to be accepted into the project.) He made his first X-15 flight on 6 October 1966. He flew the first X-15, 56-6770. A ruptured fuel tank forced him to make an emergency landing at Cuddeback Dry Lake, one of several pre-selected emergency landing sites, about 40 miles (64 kilometers) northeast of Edwards. The duration of the flight was 8 minutes, 26.4 seconds. The X-15 had only reached an altitude of 75,400 feet (22,982 meters) and Mach 3.00.

A North American Aviation X-15 at Cuddeback Lake after an emergency landing. A Piasceki HH-21C is standing by. (U.S. Air Force)

His second flight took place on 29 November 1966. On this flight, he took the # 3 ship, 56-6672, to 92,100 feet (28,072 meters) and Mach 4.65. The flight lasted 7 minutes, 55.9 seconds.

For his third flight, Mike Adams was back in 56-6670, which had been repaired. He flew to an altitude of 133,100 feet (40,569 meters) and reached Mach 5.59 (3,822 miles per hour/6,151 kilometers per hour). This was Adams fastest flight. He landed at Edwards after 9 minutes, 27.9 seconds.

Flight number four for Adams took place on 28 April 1967. Again he flew the # 1 X-15. On this flight, he reached 167,200 feet (50,963 meters) and Mach 5.44. Elapsed time was 9 minutes, 16.0 seconds.

On 15 June 1967, Adams flew # 1 to 229,300 feet (69,891 meters) and Mach 5.14. Duration 9 minutes, 11.0 seconds.

On 25 August 1967, Adams made his sixth flight, his second in the third X-15, 56-6672. The rocket engine shut down after sixteen seconds and had to be restarted. The maximum altitude was 84,400 feet (25,725 meters) and Mach 4.63. The duration of this flight was 7 minutes. 37.0 seconds.

Mike Adams’ seventh flight in an X-15 took place 15 November 1967. This was the 191st X-15 flight, and the 65th for X-15 56-6672. Tests to be conducted were an ultraviolet study of the rocketplane’s exhaust plume; solar spectrum measurements; micrometeorite collection, and a test of ablative material for the Saturn rocket.

Adams reached 266,000 feet (81,077 meters) and Mach 5.20.

Having met the U.S. Air Force qualification for flight in excess of 50 miles (80.47 kilometers), Michael Adams was posthumously awarded the wings of an astronaut.

Major Michael James Adams, United States Air Force, was buried at Mulhearn Memorial Park, in Monroe, Louisiana.

© 2018, Bryan R. Swopes

9 November 1962

McKAY, John B. (Jack) with X-15 56-6672, 13 March 1964 9 November 1962: Flight 74 of the X-15 Program was the Number Two aircraft’s 31st flight. X-15 56-6671 was carried aloft by Balls 8, the Boeing NB-52B Stratofortress, 53-008, for launch over Mud Lake, Nevada. NASA test pilot John Barron (“Jack”) McKay was to take the rocketplane to 125,000 feet at Mach 5.5 to investigate the stability and handling of the X-15 with the lower half of the ventral fin removed, and to investigate aerodynamic boundary layer phenomena.

North American Aviation X-15 56-6671 under the right wing of a B-52 Stratofortress at 45,000 feet. (NASA)
North American Aviation X-15 56-6671 under the right wing of a B-52 Stratofortress at 45,000 feet. (NASA)

The B-52 mothership dropped Jack McKay and the X-15 right on schedule at 10:23:07.0 a.m., local time, from an altitude of 45,000 feet (13,716 meters) and speed of approximately 450 knots (833 kilometers per hour). McKay advanced the throttle to ignite the Reaction Motors XLR99-RM-1 rocket engine. It fired immediately but when McKay advanced the throttle for the full 57,000 pounds of thrust, the engine remained at just 30%.

The X-15 could have flown back to Edwards Air Force Base, about 200 miles (320 kilometers) to the south, but with the engine not responding to the throttle, it was uncertain that it would continue running. The decision was made to make an emergency landing at Mud Lake.

Having reached a peak altitude of 53,950 feet (16,444 meters) and Mach 1.49 (1,109 miles per hour/1,785 kilometers per hour), Jack McKay continued to circle the lake burning off propellants as he lost altitude. The engine was shut down at 70.5 seconds. McKay positioned the aircraft for landing as he continued to dump unused propellant and liquid oxygen, but a considerable amount remained on board.

As he neared touchdown, he tried to lower the flaps but they did not deploy. The X-15 touched down on the dry lake bed at 296 miles per hour (476.4 kilometers per hour), 66 miles per hour (106 kilometers per hour) faster than normal.

Duration of the flight from air launch to touchdown was 6 minutes, 31.1 seconds.

The high speed and extra weight caused the X-15’s rear skids to hit harder than normal. When the nose wheels hit, a rebound effect placed even higher loads on the rear struts. At the same time, with the elevators in an extreme nose-up position, the higher aerodynamic loads pushed the skids deeper into the lake bed. This higher loading caused the left rear strut to collapse. The X-15 rolled to the left and the left elevator dug into the lake bed. This caused the aircraft to start sliding to the left. Jack McKay jettisoned the canopy and as the right wing tip dug into the surface, the X-15 flipped over and came to rest upside down.

A Piasecki H-21 rescue helicopter lands near the overturned X-15 at Mud Lake, 9 November 1961. (NASA)
A Piasecki H-21 rescue helicopter lands near the overturned X-15 at Mud Lake, 9 November 1961. (NASA)
The X-15 rolled over when the left landing skid collapsed because of the high-speed, overweight emergency landing at Mud Lake, Nevada. Jack McKay was trapped in the cockpit and suffered serious spinal injuries. (NASA)
The X-15 rolled over when the left landing skid collapsed because of the high-speed, overweight emergency landing at Mud Lake, Nevada. Jack McKay was trapped in the cockpit and suffered serious spinal injuries. (NASA)
The Number Two X-15, 56-6671, lies upside down and severely damaged at Mud Lake, Nevada, 9 November 1962. (NASA)
The Number Two X-15, 56-6671, lies upside down and severely damaged at Mud Lake, Nevada, 9 November 1962. (NASA)

McKay was seriously injured. He was trapped in the upside down X-15 and was in danger from the vapors of the ammonia propellants and liquid oxygen. An H-21 rescue helicopter hovered overhead to blow the vapor away.

Prior to the flight, an Air Force C-130 had brought a fire engine and crew to standby at Mud Lake, returned to Edwards and picked up a second fire engine and its crew, then remained airborne should an emergency landing be made at another intermediate dry lake.

These propositioned emergency assets were able to rescue McKay and to transport him to the hospital back at Edwards.

McKay eventually recovered sufficiently to return to flight status, but ultimately his injuries forced him to retire.

The Number Two X-15 was severely damaged. It was taken back to North American and was rebuilt into the X-15A-2, intended to reach speeds up to Mach 8. It would be more than a year and a half before it flew again.

North American Aviation X-15A-2 56-6671, after a 19-month repair, redesign and modification program. The fuselage was lengthened, additional propellant and reaction control tanks installed internally, the nose wheel and rear landing skid struts lengthened, and external tanks installed. (NASA)
North American Aviation X-15A-2 56-6671, after a 19-month repair, redesign and modification program. The fuselage was lengthened, additional propellant and reaction control tanks installed internally, the nose wheel and rear landing skid struts lengthened, and external tanks installed. (NASA)

© 2016, Bryan R. Swopes

8 November 1935

Sir Charles Edward Kingsford Smith, MC, AFC (National Archives of Australia, A1200, L93634)
Sir Charles Edward Kingsford Smith, M.C., A.F.C. (National Archives of Australia, A1200, L93634)

On 8 November 1935: Sir Charles Edward Kingsford Smith, M.C., A.F.C., and co-pilot John Thompson Pethybridge disappeared while flying Lady Southern Cross, a Lockheed Altair 8D Special, across the Andaman Sea from Allahabad, Indian Empire, to Singapore, Straits Settlements, a distance of approximately 1,932 nautical miles (2,224 statute miles, or 3,578 kilometers). The aviators were attempting to break a speed record for flight from England to Australia.

The airplane was sighted over Calcutta, British India, at 9:06 a.m., local time.

The pilot of another airplane, Charles James (“Jimmy”) Melrose, who was also en route to Australia, reported that,

“. . . he saw a ‘plane, which must have been Kingsford Smith’s, pass about 200 feet above him at 3 o’clock this morning, when he was over the Bay of Bengal, about 150 miles from land. . . Mr. Melrose said that when he passed over him in the Bay of Bengal Kingsford Smith’s speed was double his own, which was 110 miles an hour. It gave him an uncanny feeling over the desolate ocean to see the spurts of flame coming from the twin exhausts of the Lady Southern Cross. . . Kingsford Smith’s altitude was between 8000 and 9000 feet.”

The Sydney Morning Herald, No. 30,531, Saturday, 9 November 1935, Page 19, Columns 7 and 8

On 1 May 1937, about eighteen months after the disappearance, two Burmese fisherman found a landing gear assembly floating in the Andaman Sea near Kokunye Kyun (Aye Island), off the west coast of Burma. Lockheed was able to confirm that it was from Lady Southern Cross. The component is in the collection of the Powerhouse Museum, Sydney, Australia.

Landing gear assembly of Kingsford Smith’s Lady Southern Cross is in the collection of the Powerhouse Museum venue of the Museum of Applied Arts and Sciences. (MAAS Collection 94/64/1)

In 2009, searchers claimed to have located the wreck of the airplane near the island, but this has not been confirmed.

Lockheed 8-D Altair VH-USB, Lady Southern Cross, at Burbank, California, September 1935. (Unattributed)
Lockheed Altair 8D Special VH-USB, Lady Southern Cross, at Burbank, California, September 1935. The Altair is “. . . painted consolidated blue with silver wing and silver striping. . . .” (David Horn Collection No. 9099)

Kingsford Smith was a former Royal Air Force pilot and flight instructor. He had been a barnstormer, airline pilot, and gained world-wide fame for his trans-Pacific flights. From 31 May to 9 June 1928 he and Charles Ulm, Harry Lyon and James Warner had flown Southern Cross, a Fokker F.VIIB/3m, from Oakland, California to Brisbane, with stops at Hawaii and Fiji. In 1934, with Lady Southern Cross, he and Patrick Gordon Taylor flew from Australia to Hawaii and on to Oakland, California, arriving 4 November.

Charles Kingsford Smith’s Lady Southern Cross at Lockheed, Burbank, California. Note the navigator’s sighting lines on the elevators. (Code One Magazine/Lockheed Martin)

After the transpacific flight, Lady Southern Cross spent the next 11 months at Lockheed being repaired and overhauled. Kingsford Smith then flew it across the United States and had it transported to England aboard a ship.

Lady Southern Cross was a Lockheed Altair 8D Special, a single-engine monoplane with the fuselage, wings and tail surfaces built of spruce. The Altair had been modified from a 1930 Lockheed Sirius 8A Special, NR118W, c/n 152, which was an airplane with fixed landing gear. Lockheed designed a new wing which included retractable landing gear, operated by a hand crank from the cockpit. The Sirius and Altair were single-place utility transports. Kingsford Smith’s Altair was further modified with two cockpits in tandem. Lady Southern Cross was painted Consolidated Blue (a dark blue color) with silver accents.

Sir Charles Edward Kingsford Smith, MC, AFC, with the Lady Southern Cross at Croydon, 17 October 1935. The airplane's registration has been changed to G-ADUS.
Air Commodore Sir Charles Edward Kingsford Smith, Kt, MC, AFC, with the Lady Southern Cross at Croydon, 17 October 1935. The airplane’s registration has been changed to G-ADUS. (PHOTOSHOT)

Lady Southern Cross had a length of 27 feet, 10 inches (8.484 meters) with a wingspan of 42 feet, 9¼ inches (13.037 meters) and height of 9 feet, 3 inches (2.819 meters). The modified airplane had an empty weight of 3,675 pounds (1,667 kilograms) and a maximum gross weight of 6,700 pounds (3,039 kilograms).

The airplane’s standard Pratt & Whitney Wasp C1 engine was replaced at Kingsford Smith’s request with a more-powerful Pratt & Whitney Wasp SE, serial number 5222. The Wasp SE was an air-cooled, supercharged, 1,343.804-cubic-inch-displacement (22.021 liter) single-row 9-cylinder radial engine with a compression ratio of 6:1. It was rated at 500 horsepower at 2,200 r.p.m., at an altitude of 11,000 feet (3,353 meters). The SE was a direct-drive, right-hand tractor engine which turned a two-bladed Hamilton Standard controllable-pitch metal propeller with a diameter of 9 feet, 0 inches (2.743 meters). The Wasp SE was 3 feet, 6.59 inches (1.082 meters) long, 4 feet, 3.44 inches (1.307 meters) in diameter and weighed 750 pounds (340.2 kilograms).

An Altair 8D  had a cruising speed of 175 miles per hour (282 kilometers per hour) and a maximum speed of 207 miles per hour (333 kilometers per hour) at 7,000 feet (2,134 meters). Contemporary news reports stated that Kingsford Smith had reached speeds of 230 miles per hour (370 kilometers per hour) while testing VH-USB.

Sir Charles Edward Kingsford Smith, MC, AFC, At Lympne Airport, Kent, England, 6 November 1935. This may be the last photograph ever taken of "Smithy". (International News Photos)
Air Commodore Sir Charles Edward Kingsford Smith, Kt, MC, AFC, at Lympne Airport, Kent, England, 6 November 1935. This may be the last photograph ever taken of “Smithy.” (International News Photos)

© 2017, Bryan R. Swopes

5 November 1959

The Number 2 X-15, 56-6671, broke in half when it made an emergency landing while still partially loaded with propellants. (NASA)
The Number 2 X-15, 56-6671, broke in half when it made an emergency landing while still partially loaded with propellants. (NASA)

5 November 1959: During his fourth X-15 flight—the third in the Number Two ship, 56-6671—North American Aviation chief test pilot Albert Scott Crossfield made an emergency landing at Rosamond Dry Lake after one of the two Reaction Motors XLR11-RM-13 rocket engines exploded, causing an engine compartment fire.

The X-15 had been launched by the Boeing NB-52A Stratofortress, 52-003, at 0.82 Mach and approximately 45,000 feet (13,716 meters) over Bouquet Canyon Reservoir, about 35 miles (56 kilometers) southwest of Edwards Air Force Base. Scott Crossfield ignited both XLR11 rocket engines and began to accelerate and climb, but one of four combustion chambers of the lower engine exploded almost immediately. He shut both engines down after 11.7 seconds. Crossfield kept the rocketplane in a level attitude for the 114 seconds it took to jettison the liquid oxygen and water-alcohol propellants to lighten the X-15 for the landing. The tanks could not fully drain and the aircraft remained approximately 1,000 pounds (455 kilograms) overweight.

The X-15 approached the emergency landing site at Rosamond Dry Lake, about ten miles (16 kilometers) southwest of Edwards, while Major Robert M. White, flying a Lockheed F-104 chase plane, called out Crossfield’s distance from the dry lake and his altitude. As he neared the touch down point, Crossfield raised the X-15’s nose to decelerate.

“I lowered the skids and nose wheel, pulled the flaps, and felt for the lake bed.

“The skids dug in gently. The nose wheel slammed down hard and the ship plowed across the desert floor, slowing much faster than usual. Then she came to a complete stop within 1500 feet instead of the usual 5000 feet. Something was wrong; the skids failed, I was sure. . . Quickly I scrambled out of the cockpit. What I saw almost broke my heart. The fuselage had buckled immediately aft of the cockpit, two hundred and thirty inches back from the nose. Her belly had dragged in the sand, causing the abrupt deceleration on the lake. The rocket chambers which had exploded at launch were a shambles.”

Always Another Dawn: The Story of a Rocket Test Pilot, by A. Scott Crossfield and Clay Blair, Jr., The World Publishing Company, Cleveland and New York, 1960, Chapter 41 at Pages 383–384.

The scene at Rosamond Dry Lake after Scott Crossfield's emergency landing after an engine explosion. (NASA)
The scene at Rosamond Dry Lake after Scott Crossfield’s emergency landing following an engine explosion. (NASA)

It was determined that the engine had exploded due to an ignition failure, a relatively simple problem not connected to the design of the X-15. But there remained the question as to why the rocketplane had broken in half. The investigation found that the rapid extension of the nose wheel strut when lowered caused the oil inside the strut to foam and vaporize, providing almost no shock absorption. This was corrected and the check list changed to lower the gear sooner.

The total duration of this flight was 5 minutes, 28.0 seconds. The peak altitude was 45,462 feet (13,857 meters) and the maximum speed was 660 miles per hour (1,062 kilometers per hour).

56-6671 was taken back to the North American Aviation plant for repair. It returned to flight operations three months later.

Test pilot A. Scott Crossfield with the damaged X-15 (UPI/Harry Ransom Center
Test pilot A. Scott Crossfield with the damaged X-15 on Rosamond Dry Lake. (UPI/Harry Ransom Center, University of Texas at Austin)

© 2016, Bryan R. Swopes