Pratt & Whitney's Short Take Off/Vertical Landing variant F135 engine receives Initial Service Release

Pratt & Whitney, a United Technologies Corp. (NYSE: UTX) company, has achieved initial service release (ISR) for the short take off and vertical landing variant (STOVL) F135 engine, marking another major milestone. The propulsion system is now certified as the production configuration and cleared for flight in the Lockheed Martin F-35B stealth fighter. Pratt & Whitney received ISR for the conventional take off and landing/carrier variant (CTOL/CV) F135 engine in February 2010.

"Achieving initial service release for the STOVL propulsion system means all three variants of the F135 engine have met all necessary requirements and proven the safety, reliability and performance of this product. We are one step closer to powering operational flights," said Bennett Croswell, vice president of F135/F119 Engine Programs, Pratt & Whitney. "I am proud of the F135 STOVL team and our partners at Rolls-Royce, Hamilton Sundstrand and Lockheed Martin for this great program accomplishment. We look forward to seeing the F135-powered Lightning II in operational flight."

The F135 is in production and is the only engine powering the F-35 Lightning II flight test program today. The F135 CTOL/CV engine and STOVL propulsion system continues to power the F-35 Lightning II with 540 flight tests and more than 750 flight test hours. The F135 has powered all 12 vertical landings and the F135 engine is demonstrating excellent reliability, performance and thrust response. To date, Pratt & Whitney has delivered 12 production F135 engines, including the first two production STOVL propulsion systems.

Pratt & Whitney has designed, developed and tested the F135 to deliver the most advanced fifth generation fighter engine for the United States and its allies around the world. The F135 has been further enhanced with technologies developed in several U.S. Air Force and Navy technology programs.