EnginesTwo different jet engines are being developed for the F-35

Two different jet engines are being developed for the F-35; the Pratt & Whitney F135 and the General Electric/Rolls-Royce F136. The STOVL versions of both powerplants use the innovative Rolls-Royce LiftSystem, patented by Lockheed Martin and built by Rolls-Royce. This system is more like the Russian Yak-141 and German VJ 101D/E than the preceding generation of STOVL designs, such as the Harrier Jump Jet.The LiftSystem is composed of a lift fan, driveshaft, clutch, 2 roll posts and a "3 Bearing Swivel Module" (3BSM). The 3BSM is a thrust vectoring nozzle which allows the main engine exhaust to be deflected downward at the tail of the aircraft. The lift fan near the front of the aircraft provides a counter-balancing thrust. Somewhat like a vertically mounted turboprop within the forward fuselage, the lift fan is powered by the engine's low-pressure (LP) turbine via a driveshaft and gearbox. Roll control during slow flight is achieved by diverting pressurized air from the LP turbine through wing mounted thrust nozzles called Roll Posts.