"Gerry" Sayer flew Britain's maiden jet flight in Sir Frank Whittle's Gloster E.28/39 (Pioneer), an aircraft designed by George Carter, on 15 May 1941.

Sayer joined the Royal Air Force on 30 June 1924, being granted a short service commission with the rank of probationary pilot officer,[1] and was posted to No.

[4] He learnt to fly in an Avro 504K, and later flew Sopwith Snipes, before becoming a test pilot at RAF Martlesham Heath, the home of the Aeroplane and Armament Experimental Establishment.

Sayer was transferred to the Reserve of Air Force Officers (Class A) on 2 March 1929,[5] to become second test pilot with Hawker Aircraft, assistant to Group Captain P. W. S. (George) Bulman (who first flew the Hurricane on 6 November 1935).

[8] On 15 May 1941 at 7.45pm, he took off from RAF Cranwell, near Sleaford in Lincolnshire in the Gloster E.28/39 (W4041/G) powered by the W.1 engine and flew for 17 minutes, flying at over 500 miles per hour (800 km/h),[9] impossible for other aircraft at the time in level flight.