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F-35 Lightning II News

F-35 STOVL team completes successful gearbox test

May 7, 2007 (by Lieven Dewitte) - Pratt & Whitney and Rolls-Royce successfully completed the first phase and initiated phase two of the F135 short-takeoff/vertical-landing engine LiftFan gearbox qualification test.

Most of the initial STOVL tests occured over a ten feet deep conrete pit covered with a thick metal grate. The pit reduced the ground effects produced from the engine and lift fan, and it allowed engineers to study vertical flight modes while the aircraft was on the ground. [LMTAS photo]

The high-technology gearbox is a critical component that allows the STOVL F-35 Lightning II to achieve the aircraft's signature vertical-lift capability. The test includes a three-step process with the LiftFan(R) gearbox ultimately being operated 30 percent above maximum operational requirements. The test will be used to evaluate and validate the current lightweight gearbox design at the specification thrust rating for the life of the F135 propulsion system.

"Completion of this initial test is a significant step in the qualification of Pratt & Whitney's F135 in a STOVL configuration," said Bill Gostic, vice president, Pratt & Whitney F135 Program. "Our priorities are to deliver an engine that exceeds our customers' expectations and to successfully hit every milestone in the F135 STOVL development program, culminating with the first flight of the STOVL F-35 Lightning II in 2008."

The F135 engine has logged more than 7,400 system design and development ground test hours and continues to power the F-35 Lightning II's flight test program.

Pratt & Whitney is the lead propulsion system supplier for the F-35 program. The technologically advanced F135 is an evolution of the highly successful F119 engine for the F-22 Raptor. Together the F135 and F119 will have logged more than 800,000 hours before the F-35's introduction into operational service in 2012. Rated at more than 40,000 pounds of thrust, the F135 is the most powerful fighter engine ever built.

Additional images:

Following a vertical take off, the X-35B holds a stationary position 25 feet above the ground at Lockheeds Palmsdale plant on June 24th 2001. Pilot Simon Hargreaves described the flight as a stunning success. [LMTAS photo]

The X-35B in the hover with the lift-fan rotated through 90 degrees. [LMTAS photo]