Tag Archives: Geoffrey Raoul de Havilland Jr.

27 September 1946

Geoffrey Raoul de Havilland, Jr., OBE. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)
Geoffrey Raoul de Havilland, Jr., O.B.E. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)

27 September 1946: Geoffrey Raoul de Havilland, Jr., O.B.E., Chief Test Pilot of the de Havilland Aircraft Co., Ltd., and the son of the firm’s founder, was killed during a test flight of a prototype DH.108 Swallow, TG306.

Geoffrey de Havilland, Jr., in the cockpit of the second DH.108 Swallow prototype, TG/306. (Flight)
Geoffrey de Havilland, Jr., in the cockpit of the second DH.108 Swallow prototype, TG306. (FLIGHT)

De Havilland had taken off from the company airfield at Hatfield at 5:26 p.m. for a planned 45 minute flight. Flying over the Thames Estuary, east of London, England, de Havilland put the swept-wing jet into a high-speed dive from 10,000 feet (3,048 meters). As it approached 5,000 feet (1,524 meters) at 0.88 Mach, (658 miles per hour, 1,060 kilometers per hour), the shock waves building up along the wings’ leading edges disrupted the air flow over the wings, causing them to stall. TG306 pitched violently downward. A NASA report called this “. . . an undamped violently divergent longitudinal pitching oscillation at Mach 0.875. . . .”  The extreme aerodynamic loads cracked the main spar and both wings failed. The DH.108 crashed into Egypt Bay, Gravesend, Kent.

The wreck was located the following day. The body of Geoffrey de Havilland was found ten days later. He had suffered a broken neck and fractured skull as a result of his head striking the canopy during the violent oscillations of the aircraft.

(Grace’s Guide)

FLIGHT reported:

Geoffrey de Havilland was one of the outstanding test pilots in the country, and his work has played a vital part in the perfecting of such noteworthy types as the Mosquito, Hornet, Vampire and 108. His death is a serious blow not only to the company but to the country, for in the exploration of the unknown threshold of sonic flight, a combination of skill and cool courage are qualities demanding the utmost of test pilots. Geoffrey de Havilland had these qualities in a very high degree.

FLIGHT and AIRCRAFT ENGINEER, No.1971, Vol. 1, Thursday, 3 October 1946, at page 364

De Havilland DH.108 TG/306. (Unattributed)
De Havilland DH.108 TG306. (Unattributed)

The DH.108 was a single-seat, single-engine jet fighter prototype with swept wings and no conventional tail. It was similar in configuration to the Messerschmitt Me-163 rocket-powered interceptor. The first two prototypes, TG283 and TG306, were built using production English Electric DH.106 Vampire F.I fuselages. TG283 had a 43° sweep to the wings’ leading edge, while TG306 had a 45° sweep. The airplane was powered by a de Havilland Goblin 3 centrifugal-flow turbojet engine (a development of the Halford H.1) which produced 3,350 pounds of thrust (14.90 kilonewtons).

The first and third DH.108s also crashed. VW120 was destroyed on 15 February 1950 when it crashed after a dive. The left wing had separated and the pilot, Squadron Leader Stuart Muller-Rowland, also suffered a broken neck as a result of the airplane’s violent oscillations. On 1 May 1950, while conducting low-speed tests, TG283 went into an inverted spin. Squadron Leader George E.C. Genders, AFC, DFM, bailed out but his parachute did not open before he hit the ground and he was killed.

Geoffrey de Havilland, Jr., exits the cockpit of one of the company's jet aircraft. (Photograph Courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)
Geoffrey de Havilland, Jr., OBE, exits the cockpit of a DH.108 Swallow prototype. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)

© 2018, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

20 September 1943

Geoffrey de Havilland, Jr., exits the cockpit of one of the company's jet aircraft. (Photograph Courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)
Geoffrey de Havilland, Jr., exits the cockpit of one of the company’s jet aircraft. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)

20 September 1943: Geoffrey Raoul de Havilland, Jr., chief test pilot of the de Havilland Aircraft Co., Ltd., made the first flight in the prototype DH.100, LZ548/G, at Hatfield, Hertfordshire. (The “/G” in the identification indicated that the aircraft was to be guarded at all times.) Assigned the code name Spider Crab,  the production DH.100 would be better known as the de Havilland Vampire.

The flight lasted approximately 30 minutes and the airplane exceeded 400 miles per hour (644 kilometers per hour). De Havilland reported that the prototype was trimmed with the left wing down, had overly sensitive ailerons and demonstrated instability in yaw with rudder applications.

This oscillation in the yaw axis—called “snaking”—was determined to be a result of the overly effective vertical fins. After wind tunnel and flight testing, it was decided to reduce the fins’ area, resulting in the flat top configuration seen in bottom photograph.

Right front view of the first prototype de Havilland DH.100, LZ548/G.
Right front view of the first prototype de Havilland DH.100, LZ548/G, prior to its first flight. The letter “P” in a circle next to the RAF insignia identifies the airplane as a prototype. The “/G” in the identification number indicates that a guard is required at all times. (De Havilland Aircraft Co., Ltd.)

The DH.100 was a single-seat, single-engine fighter powered by a turbojet engine. The twin tail boom configuration of the airplane was intended to allow a short exhaust tract for the engine, reducing power loss in the early jet engines available at the time.

Right side view of the de Havilland DH.100 Spider Crab LZ548/G.
Right side view of the de Havilland DH.100 Spider Crab LZ548/G.

LZ548/G was originally powered by a Halford H.1 turbojet which produced 2,300 pounds of thrust (10.231 kilonewtons) at 9,300 r.p.m. This engine was produced by de Havilland and named Goblin.

av_gb_4603_jet-history_goblin_p080_w     The Goblin is a linear descendant of the early Whittle units. It comprises a single-sided centrifugal compressor delivering air to sixteen combustion chambers grouped symmetrically around the axis of the unit and leading to the nozzle of the single-stage axial turbine which drives the compressor. Compressor impeller and turbine rotor are coupled by a tubular shaft to form a single rotating assembly which is mounted on only two ball bearings. The maximum diameters of the engine, around the compressor casing, is 50in., [1.27 meters] and with a jet pipe of minimum length fitted the overall length is about 8ft. [2.438 meters] Equipped with a jet pipe and all the necessary engine auxiliaries the dry weight of the complete unit is 1,500 lb. [680 kilograms] Fuel consumption is at the rate of 1.23 lb. / hr. per lb. thrust.

FLIGHT and AIRCRAFT ENGINEER, No. 1923. Vol. XLVIII. Thursday, 1 November 1945 at Page 472, Column 2

The Vampire entered service with the Royal Air Force in 1945 and remained a front-line fighter until 1953. 3,268 DH.100s were built.

Right rear quarter view of the prototype de Havilland DH.100, LZ548/G.
Right rear quarter view of the prototype de Havilland DH.100, LZ548/G. In this photograph, the airplane’s vertical fins have been squared off. This would be a feature of the production Vampire F.1.

The first of the three prototype Vampires, LZ548, crashed after takeoff from Hatfield, 23 July 1945, due to a fuel pump failure. Geoffrey Pike, the pilot, was not injured.

© 2016, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather