John Derry

John Douglas Derry DFC (5 December 1921 – 6 September 1952) was a British test pilot, and was the first Briton to exceed the speed of sound. He was killed in the 1952 Farnborough Airshow DH.110 crash (The DH.110 went on to become the de Havilland Sea Vixen) where his aircraft broke up because of a design fault, with 29 fatalities including himself and his flight observer Tony Richards.

Born in Cairo, Egypt, Derry attended Dragon School in Oxford and Charterhouse School. Shortly after the outbreak of World War II he left school to enlist as a wireless operator and air gunner in the Royal Air Force. In 1942 he received a commission and the following year trained (in Canada) as a pilot. His operational career began late in 1944 when he joined 182 Squadron, flying Hawker Typhoons on close support to the Allied armies in the Low Countries. After serving also with 181 Squadron, he was given command of 182 Squadron shortly before the end of the war.

In 1947 Derry joined de Havilland as a test pilot, working largely on the de Havilland DH 108 aircraft. He is widely believed to have exceeded the speed of sound on 6 September 1948 when he lost control of his aircraft and the Mach meter briefly showed supersonic speeds in a shallow dive from 12,195 m (40,000 ft) to 9,145 m (30,000 ft), although recording apparatus was switched off.