One of the best known examples of thrust vectoring in an engine is the Rolls-Royce Pegasus engine installed in the Hawker Siddeley Harrier. Although thrust vectoring with the Harrier, also called "Vectoring In Forward Flight" or VIFFing, is actively discouraged by the Royal Air Force and Royal Navy, it is encouraged and actively practiced by the United States Marine Corps. This technique has been used in various experimental and development planes, some with vectored thrust in directions other than downwards.
The Lockheed Martin F-35 Lightning, currently in its development stage, incorporates a conventional afterburning turbofan which facilitates supersonic operation, together with a vertically mounted, low pressure shaft-driven remote fan, driven through a clutch during landing from the engine. The exhaust from this fan is deflected by a thrust vectoring nozzle to provide the appropriate combination of lift and propulsive thrust during transition.
The Sukhoi Su-30 MKI, powered by two AI-31FP afterburning turbofans, is an aircraft that employs 2D thrust vectoring, which makes it highly maneuverable. The Su-30 is capable of near-zero airspeed at high angles of attack and dynamic aerobatics in negative speeds up to 200 km/h. The thrust vectoring nozzles of the MKI are mounted 32 degrees outward to the longitudinal engine axis and can be deflected approximately 15 degrees in the vertical plane. This produces the cork-screw effect and enhances the turning capability of the aircraft.
|