In the mid 1980s design work began on the U. S. Air Force's next generation air superiority fighter. The F-22 team, consisting of Lockheed, Boeing, and General Dynamics, embraced a design philosophy in which low observable technology, maneuverability, and supersonic performance were given equal consideration. Even with low observable features and long range weapon employment capabilities, the team believed that the probabilities of brief, short range air combat engagements, based on historical precedents and postulated future scenarios, demanded a highly agile design. Thrust vectoring emerged as a key feature for obtaining the desired agility without adversely impacting the aircraft's low observable signature. Thrust vectoring technology was incorporated and flown in the YF-22 Advanced Tactical Fighter prototype to investigate and validate the concept for the production F-22. The airframe, flight control system, and propulsion system were fully integrated. Thrust vectoring commands were generated by the aircraft's flight control computers and sent to each engine controller. Each engine controller independently performed the computations and issued the commands necessary to position the nozzle actuators to the correct vector angle while maintaining commanded thrust levels and engine stall margin. Flight tests showed that thrust vectoring provided major improvements in low speed maneuverability, enhanced handling qualities during tracking, and increased supersonic sustained turn performance as compared to current front line fighters.
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