World's Most Powerful Jet Engine Will be Flown at Farnborogh - Being flight tested in this Short S.A. 4 Sperrin bomber prototype is the de Havilland Gyron, the most powerful jet engine in the world.It is fitted in the lower port nacelle of the plane, which will fly with it at the Farnborough air show.The engine has been designed specifically for aircraft which will operate at speeds above the speed of sound and more than five years have been spent in its development. September 02, 1955. (Photo by Reuterphoto).