Lockheed Martin [LMT] yesterday rolled out the Marine Corps’ F-35B short takeoff/vertical landing variant of the Joint Strike Fighter, a little over a year since the first F-35 took its inaugural flight.
The F-35B, designed to replace Marine Corps AV-8Bs and F/A-18s, is one of three variants of the Lightning II. Its first flight is planned for mid-2008, following a series of extensive ground tests. The F-35A conventional takeoff and landing version began its flight test program in December of 2006. The F-35C, designed for catapult launches and arrested recoveries aboard aircraft carriers, will make its inaugural flight in 2009, according to Lockheed Martin.
The heart of the F-35B is a STOVL propulsion system comprising the most powerful engine ever flown in a jet fighter, a shaft-driven counter-rotating lift fan situated behind the cockpit, a roll duct under each wing for lateral stability, and a rear 3-bearing swivel nozzle that vectors engine exhaust in the desired direction, the company said.
During vertical or short takeoffs, or vertical landings, doors above and below the lift fan open, and a clutch connecting the lift fan to the engine drive shaft engages. A dorsal auxiliary engine inlet opens to increase airflow to the engine. At the same time, doors beneath the 3-bearing swivel nozzle open and the rear nozzle pivots downward, deflecting engine thrust toward the ground. Roll ducts under each wing also are engaged, keeping the aircraft laterally stable. In this configuration, the F-35B can hover, land vertically, take off in a few hundred feet fully loaded, or take off vertically with a light load. When the aircraft transitions from jet-borne to conventional wing-borne flight, the doors close and the pilot can then accelerate to supersonic speeds. The system is completely automatic, Lockheed Martin said.
The Pratt & Whitney [UTX] F135 engine will power the first series of F-35Bs. The F136, an interchangeable engine under development by the General Electric [GE] Rolls-Royce Fighter Engine Team, will make its first F-35 flight in 2010. Rolls-Royce produces the shaft-driven lift fan, 3- bearing swivel nozzle and roll duct systems, Lockheed Martin added.
An additional six development STOVL F-35s are now in production across the worldwide F-35 supply chain. In 2007, long-lead procurement funds for the first six production STOVL aircraft were authorized, with the first Marine Corps training jets planned for a 2011 delivery, the company said.
The first flight of Lockheed Martin’s conventional takeoff and landing (CTOL) took place Dec. 15, 2006 (Defense Daily, Dec. 18, 2006).