UPDATE 1-GE, Rolls to redesign part of F-35 engine
* Engine should be "up and running" before end of year
* Analyst says issue raises questions about 2nd engine (Adds details from GE-Rolls statement, analyst blog)
WASHINGTON, Nov 2 (Reuters) - General Electric Co (GE.N) and Rolls-Royce Group PLC (RR.L) said on Monday they will redesign a small part of the alternate F-35 fighter engine they are developing, after a nut came loose during testing.
Rick Kennedy, a GE spokesman, told Reuters the companies expected to have the reworked F136 engine "up and running before the end of the year."
He said the redesign involves a diffuser that directs air into the combustor for the engine, and the combustor was performing as expected.
President Barack Obama last week signed the fiscal 2010 defense authorization law, which authorizes funding for the second engine despite the administration's drive to eliminate it in the current fiscal year.
But funding for the program could still be curtailed by House and Senate appropriators who plan to wrap up their work on the fiscal 2010 defense appropriations bill this month, which means any problems with the two F-35 engines are being closely watched.
Defense Department spokesman Geoff Morrell last week said the Pentagon remained unhappy about congressional efforts to continue funding the alternate engine.
Backers of the alternate engine program say the competition will cut engine costs in the long run and reduce the risk of a fleet-wide grounding because of any potential design or mechanical flaw.
Pratt & Whitney, a unit of United Technologies Corp (UTX.N), builds the primary engine for the F-35 fighter jet being developed by Lockheed Martin Corp (LMT.N). Its engine has also encountered problems during testing, necessitating some changes.
Defense analyst Loren Thompson, in a blog on the website of his Lexington Institute, said on Monday that the GE-Rolls engine had "run into problems" and "repeated failures," incurring four failures during just 52 hours of testing after nine months of development.
At the same stage, the Pratt & Whitney engine had undergone 700 hours of system design and development (SDD) testing with no failures, Thompson said.
GE's Kennedy confirmed there had been four issues during 52 hours of testing, but said the GE-Rolls team had done engine tests for two years and accumulated 800 hours on actual hardware before the current SDD phase began.
"Thompson is comparing apples to oranges on the SDD test hours," he said, noting that the two teams' system design and development phases were "different because of different funding levels."
Kennedy said the Pratt engine also continued to experience problems after 10,000 hours of testing. "I raise this not to challenge Pratt & Whitney's ability, but to underscore how difficult developing these engines truly is," he said.
He also denied that rising costs on the F-35 program were due to the alternate engine.
Thompson said continued funding for the second engine was problematic, since it also raised the prospect for more design issues. "With several billion dollars remaining to be spent before the alternate engine joins the fleet, there is still time to rethink whether a second engine is really needed," Thompson said. (Reporting by Andrea Shalal-Esa; Editing by Tim Dobbyn)