Tailless Plane Exceeds Speed of Sound

Grey River Argus, 11 September 1948, Page 4

Tailless Plane Exceeds Speed of Sound

LONDON, September 9. The Supply Ministry announced that the de Havilland 108, a research plane, piloted by John Derry, is believed to have exceeded the speed of sound —about 720 miles an hour —in a recent high-speed development trial. The de Havilland 108 is a small tailless plane with one central jet engine, and looks like a bat. It was built specially for research into the problems of the de Havilland “flyingwing”, which i# a 40-seat jet-liner being constructed in the utmost secrecy. Mr Geoffrey de Havilland was killed in September, 1946, while flying at over 600 miles an hour in a de Havilland 108. (Rec. 10.0). LONDON, Sept. 10. The Ministry of Supply statement on Derry’s faster-than-sound flight says:—“The plane recorded an apparent mach number iif excess of one.” “The Times” aviation correspondent says that the mach number is a means of expressing speed in relation to the velocity of sound. A mach number of one indicates the sonic t speed—762 miles hourly at sea level, 'decreasing with altitude to 660 miles at 40,000 feet. The Ministry’s announcement means that the plane exceeded the speed of sound at the height at which it flew. The “Daily Mail” understands that Derrv was living at 35,000 feet. Tne speed is believed to have been nearly 700 miles an hour. Derry is a 26-year-old test pilot and war-time R.A.F. flyer. Derry, in March, 1948, brke the world’s record for the 100 kilometre closed . circuit by flying a D.H. 108 at an average of 605 miles an hour.