 It is notable for being the first British jet engine to fly, as the "Whittle Supercharger Type W1", powering the Gloster E.28/39 on its maiden flight at RAF Cranwell on 15 May 1941.The W.1 was superseded by the Power Jets W.2.After a period of indifference, in June 1939 a demonstration of the Power Jets WU was made before a delegation of the Air Ministry, notably Dr Pye, Director of Scientific Research.