Gloster-Whittle E28/39, c 1940s. The Gloste

UNITED KINGDOM - SEPTEMBER 12: Gloster-Whittle E28/39, c 1940s. The Gloster-Whittle E28/39 was the first Allied jet aircraft, which first flew briefly on 8 May 1941 while on taxiing trials although its first official flight was on 15 May. The airframe was built by Gloster Air Company and proved the turbojet concept which had been under development by Frank Whittle (1907-1996) and his company since 1936. The E28/39 was the forebear of the Gloster Meteor which saw active service in WWII. The E28/39 was surprisingly successful considering the novelty of the technology it used, and was the first real proof that jet propulsion was a viable alternative to the propeller. (Photo by SSPL/Getty Images)