Tuesday 11 January 2011

De Havilland DH 108 Swallow



The De Havilland DH 108 was a British experimental aircraft designed by John Carver Meadows Frost in October 1945. The DH 108 featured a tailless, swept wing with a vertical tail, closely resembling the layout of the wartime German Messerschmitt Me 163 Komet rocket powered point-defense interceptor. Initially designed to evaluate swept-wing handling characteristics at low and high subsonic speeds for the proposed early tailless design of the Comet airliner, three examples of the DH 108 were built to the Air Ministry specifications E.1/45 and E.11/45 .for the programme: TG283, TG306 in 1946 and VW120 in 1947.


With the adoption of a conventional tail for the Comet, the aircraft were used instead to investigate swept wing handling up to supersonic speeds. All three prototypes were lost in fatal crashes.


While being used to evaluate handling characteristics at high-speed, on 27 September 1946 TG306 suffered a catastrophic structural failure that occurred in a dive from 10,000 ft (3,050 m) at Mach 0.9 and crashed in the Thames Estuary. The pilot, Geoffrey de Havilland Jr., was killed in the accident.


Captain Eric "Winkle" Brown flew one of the two remaining aircraft at Farnborough in the late 1940's and described it as a death trap. The cockpit hood was very low and as a small man he thinks he was lucky not to smash his head on it when he experienced heavy "buffeting". He recovered the aircraft and is of the opininion that as a very tall man Geoffrey de Havilland Jr may well have been hurt and lost consciousness while experiencing the same conditions.


TG283 crashed on 1st May 1950 killing the pilot George Genders whilst carrying out stalling trails at Hartley Wintney. VW120 crashed on 15 February 1950 at Little Brickhill whilst involved in transonic dive research, killing the pilot Squadron Leader Stuart Muller-Rowland. The test flight was supposed to examine the effects of change from sub-sonic to transonic flight, but the aircraft is thought to have broken up whilst in a dive. The inquest into Muller-Rowland's death was opened two days later by North Bucks Coroner Mr E T Ray at Bletchley. Witnesses told of hearing an explosion. (Note: it is not clear if this "explosion" was the cause of the aircraft breaking up or a sonic boom.)
Some of the wreckage came down at Little Brickhill, the cockpit came down somewhere near Bow Brickhill church. Other pieces were found as far away as Husborne Crawley. Muller-Rowland's body was found near Sandy Lane between Bow Brickhill and Woburn Lane. Woburn, Bletchley and Leighton Buzzard fire brigades were all called out to attend the accident. Because of the secrecy of the aircraft the local police sealed the area to keep the public away, and after the crash police officers visited local schools to appeal for any 'souvenirs' to be returned.
Stuart Muller-Rowland was born on 27th November 1921 in Woking, Surrey. During the war he flew Bristol Blenheim bombers with 60 Squadron in India, later flying Bristol Beaufighters with 211 Squadron in Burma. After the war, with the rank of Squadron Leader, he joined the Empire Test Pilots School, completing No. 6 course. He was posted to the Royal Aircraft Establishment in 1948 and was named DH 108 pilot for the high speed programme.

VW120 was the first British aircraft to break the sound barrier on 6th September 1948 piloted by John Derry. In fact VW 120 was only the third aircraft ever to fly at Mach 1. VW 120's first flight was on 24th July 1947 piloted by John Cunningham. The three de Havilland 108 aircraft made a total of 480 flights that greatly explained a lot of the questions that needed to be answered about the transition to sonic flight, although all three aircraft eventually crashed killing their test pilots. Unofficially the DH 108 was known as "The Swallow".

More on the Derry Farnborough crash featuring period newspaper coverage on this blog here