30 May 1949: While testing a radical “flying wing” aircraft, the Rolls-Royce Nene-powered Armstrong Whitworth A.W.52, TS363, test pilot John Oliver (“Jo”) Lancaster, D.F.C., encountered severe pitch oscillations in a 320 mile per hour (515 kilometer per hour) dive. Lancaster feared the aircraft would disintegrate.
In the very first use of the Martin-Baker Mk1 ejection seat in an actual emergency, Lancaster fired the seat and was safely thrown clear of the aircraft. He parachuted to safety and was uninjured. The aircraft was destroyed.
The Martin-Baker MK1 was developed by Bernard Ignatius (“Benny”) Lynch, B.E.M., a ground fitter for Martin-Baker Aircraft Co., Ltd., who tested it himself, ejecting from a test aircraft at 420 miles per hour (676 kilometers per hour) and 12,000 feet (3,658 meters). He eventually made more than 30 ejections. Lynch was awarded the British Empire Medal in the King’s 1948 New Year Honours.
The seat was launched with a two cartridge ejection gun, with an initial velocity of 60 feet per second (18.3 meters per second). After rising 24 feet (7.3 meters), a static line fired a drogue gun, deploying a 24-inch (0.61 meter) drogue parachute to stabilize the seat. The static line also actuated the seat’s oxygen supply. The pilot manually released himself from the seat, and opened his parachute by pulling the rip cord.
As of 30 May 2020, 7,620 airmen worldwide have been saved by Martin-Baker ejection seats. 69 of these were with the Mk1.
The Armstrong Whitworth A.W.52 was an all-metal, experimental two-place, twin engine, tailless “flying wing” airplane with retractable tricycle landing gear. The concept was that of an air mail aircraft. The cockpit was pressurized and offset to the left of the aircraft centerline. The two turbojet engines are in nacelles positioned almost entirely within the wing. The A.W.52 was 37 feet, 4 inches (11.354 meters) long with a wingspan of 90 feet (27.4 meters) and height of 14 feet, 4 inches (4.343 meters).
The wings were swept in two sections. From the fuselage to just outboard of the engines, the leading edges were swept to 17° 34′. From that point, called “the knuckle” in contemporary descriptions, the sweep increased to 34° 6′ to the wing tips. (A line from the ¼-chord points at the wing root and tip gave a sweep of 24¾°.) The inner wing had no dihedral, and the outer wing had 1° dihdreal. The wing incorporated a -5° twist between the root and tip. The total wing area was 1,314 square feet (122.1 square meters). Vertical fins and rudders are attached at the wing tips.
The airplane incorporated boundary layer control to delay the wing stalling in the area of the ailerons. It also used engine heat for deicing,
The A.W.52 had a empty weight of 19,662 pounds (9,055 kilograms) total weight of 32,700 pounds (14,832 kilograms).
The A.W.52 was powered by two Rolls-Royce RB.41 Nene Mk.I engines. The Nene was a single-shaft turbojet developed from the RB.40 Derwent. It had first been run in October 1944. The Nene was considerably larger than the Derwent and produced nearly double the thrust. It had a single-stage centrifugal-flow compressor and single-stage axial-flow turbine. It was rated at 5,000 pounds of thrust (22.24 kilonewtons) at 12,400 r.p.m. for takeoff. The second A.W.52 prototype, TS368, used two Derwent engines.
The A.W.52 had a maximum speed at Sea Level of 500 miles per hour (805 kilometers per hour) and 480 miles per hour (772 meters) at 36,000 feet (10,973 meters). Its maximum range was 1,500 miles (2,414 kilometers), flying 330 miles per hour (531 kilometers per hour) at 36,000 feet (10,973 meters).
© 2018, Bryan R. Swopesby