By Marina Malenic

WEST PALM BEACH, Fla.–The manufacturer of an engine that powers a jump-jet version of the F-35 Joint Strike Fighter is confident that engineering challenges facing the engine will be resolved this year.

“By the end of 2011, no one will be talking about difficulties with this engine,” Warren Boley, the head of Pratt & Whitney’s military engine business, told Defense Daily in a March 31 interview.

Pratt & Whitney, a division of United Technologies [UTX], builds the F135 engine that powers all three variants of the F-35–a conventional variant for the Air Force; a short take-off and vertical landing (STOVL) variant for the Marine Corps; and a carrier variant for the Navy. Lockheed Martin [LMT] is developing the airplane.

Earlier this year, Defense Secretary Robert Gates announced a “probation” period for the STOVL variant, which has encountered more developmental challenges than the other two, simpler models (Defense Daily, Jan. 7). The Marines have said they need the STOVL variant to replace the 25-year-old AV-B Harrier, which is used when landing on amphibious warfare vessels and improvised airstrips.

Boley said his company can complete all necessary improvements to the engine by the third quarter of fiscal 2011.

“If there are still problems at that time, I know they won’t be with the engine,” he said. He added that he does not have “visibility” into the avionics or any other airframe- specific problems that Lockheed Martin may be having.

“With the engine, we are dealing purely with application engineering at this point,” he added. “Tech development is complete.”

Meanwhile, Pratt & Whitney is preparing to submit a pricing proposal for the sixth low-rate initial production (LRIP) batch of F135s to the Pentagon by the end of the month. According to United Technologies CEO David Hess, the company was able to provide a 16 percent cost cut on LRIP 6 and is on track to keep reducing costs with each follow-on production batch by 13 percent.

Earlier this year, executives from the company said they would require an additional $1 billion to add flight-test engines and related support to the program after Gates restructured the F-35 program as a whole. An extended development timeline and additional flight testing will likely mean that four to six flight-test engines will be added to the current fleet of 18, according to Boley.

He added that about $600 million to $700 million of the $1 billion would be flight-test costs, while the remainder accounts for incremental “product improvement” demanded by the F-35 Joint Program Office following a technical baseline review completed earlier this year. Most of those improvements relate to maintainability and field support, according to Boley.