Pratt & Whitney, a division of United Technologies [UTX], has delivered the first production F135 Short Take Off/Vertical Landing (STOVL) engine for the Lockheed Martin-built [LMT] F-35 Joint Strike Fighter, the company said yesterday.

“The F135 engine program accomplishments this year have been historical, and this first production STOVL delivery milestone demonstrates our commitment to fielding the most advanced military jet engine technology to the benefit of the warfighter,” said Bennett Croswell, vice president of F119/F135 Engine Programs for Pratt & Whitney.

The F135 propulsion system has powered 509 flights and more than 740 flight test hours to date, according to the company. The F135 has also completed more than 20,000 hours of testing–3,600 test hours during the concept demonstration phase, 15,800 test hours during development and more than 700 hours powering the F-35 flight test program.

The Conventional Takeoff and Landing (CTOL)/Carrier Variant (CV) engine received Initial Service Release (ISR) in February 2010, indicating that the engine has met the ISR requirements for safety, reliability, durability and performance, and that it is now cleared for use in the field. Pratt & Whitney has delivered all F135 flight test engines required for the program as well as 11 production engines, which includes the first STOVL F135 delivery.

The STOVL F135 engine has completed all required testing and is on track to receive ISR certification before the end of the year, according to a Pratt & Whitney press statement.