Jet V/STOL Propulsion Systems Of The 20th Century

With 2010 being the 50th anniversary of the first test flights of the P.1127 - which resulted in the world's first operational jet aircraft with vertical and/or short take-off and landing (V/STOL) capability – it is appropriate to look back at the history of jet engines and exhaust systems that were purpose-designed for vertical flight, beginning with the modifications in the United Kingdom to the Rolls- Royce Nene engines used on the Flying Bedstead in 1954. The British development of the Rolls-Royce RB108 lift engine was followed by collaboration with the French for the RB162 variants, with the Germans on the RB145, and the US for the Rolls- Royce/Allison XJ99. Also in the UK, the Bristol Pegasus saw a long line of developments over a half-century, as well as several variants that were tested, but never put into production. Innovative lift/cruise nozzles were developed for otherwise conventional engines for application to fighter and cargo aircraft. In the US, General Electric modified conventional jet engines to operate as lift engines. The US funded development of a "three-bearing swivel nozzle" - the legacy of which resulted in the Lockheed Martin F-35 engine. In the Soviet Union, jet engines were modified for their Turbolyot flying test rig, followed by dedicated lift engines; lift/cruise engines with new exhaust vectoring nozzles were developed for the Yakovlev Yak-36, Yak-38 and Yak-141. The rich history of developing these and other jet engines for vertical flight is covered in this, the twentieth paper in the V/STOL history series.