Frank Whittle signed RAF cover

Frank Whittle (1907 - 1996) was an English engineer & RAF air officer credited with inventing the turbojet engine. During his time at the officer training course at Cranwell he devised the fundamental concepts that led to the creation of the turbojet engine, for which he took out a patent in 1930. Despite a lack of funding or Air Ministry support Whittle formed Power Jets Ltd to build his engine with a prototype first running in 1937. Following this success official contracts were placed to continue development and the maiden flight took off on the 15^th May 1941 from Cranwell flying for 17 minutes.