The record was set on 28 July 1976 by Eldon W. Joersz and George T. Morgan Jr. near Beale Air Force Base, California, USA.
[47] SR-71 pilot Brian Shul claimed in The Untouchables that he flew in excess of Mach 3.5 on 15 April 1986, over Libya, in order to avoid a missile.
[48] Although the official record for fastest piston-engined aeroplane in level flight was held by a Grumman F8F Bearcat, the Rare Bear, with a speed of 850.23 km/h (528.31 mph), the unofficial record for fastest piston-engined aeroplane in level flight is held by a British Hawker Sea Fury at 880 km/h (547 mph).
Both were demilitarised and modified fighters, while the fastest stock (original, factory-built) piston-engined aeroplane was unofficially the Supermarine Spiteful F Mk 16, which "achieved a speed of 494m.p.h.
[49] The unofficial record for fastest piston-engined aeroplane (not in level flight) is held by a Supermarine Spitfire Mk.XIX, which was calculated to have achieved a speed of 1,110 km/h (690 mph) in a dive on 5 February 1952.