Farnborough Airshow crash
On 6 September 1952, a prototype de Havilland DH.110 jet fighter crashed during an aerial display at the Farnborough Airshow in Hampshire, England. The jet disintegrated mid-air during an aerobatic manoeuvre, killing pilot John Derry and onboard flight test observer Anthony Richards.
Source: Wikipedia — Farnborough Airshow crash (CC BY-SA 4.0)