Gloster-Whittle E28/39 jet aeroplane, 1941.
© Science Museum / Science & Society Picture Library
The E28/39 was the first Allied jet aircraft and it had its first official flight on 15th May 1941. The airframe was built by Gloster Air Company and proved the turbojet concept which had been under development by Frank Whittle and his company since 1936. The E28/39 was surprisingly succesful considering the novelty of the technology it used, and was the first real proof that jet propulsion was a viable alternative to the propeller.