Sen. Joseph I. Lieberman says the Pentagon has withheld information about a test failure of the F-35 Joint Strike Fighter alternative engine at a critical time: as lawmakers are determining whether to fund the program.

The fiscal 2010 Defense appropriations conference report (HR 3326) is nearly complete, but it has been delayed because Democratic leaders might use the bill as leverage to help pass more-contentious legislation or as a vehicle for other spending bills.

In a Nov. 4 letter, Lieberman, I-Conn., wrote that “it is critical that the [F-35 Joint Program Office] explain the root cause of this incident, planned remedial actions, and likely schedule and cost impacts so that Congress can make final decisions on appropriations for the Department of Defense for the fiscal year 2010.”

Connecticut-based Pratt & Whitney, which is developing the F135 engine, and General Electric (GE), which is developing the F136 engine, are in a high-stakes competition to supply engines for the roughly 2,500 F-35 fighter jets the U.S. government intends to buy over the next 30 years for the Air Force, Navy and Marine Corps. Each contractor has spent millions of dollars lobbying lawmakers.

The House-passed Defense spending bill would provide $560 million to fund the alternative engine; the Senate-passed version did not include funding. The White House opposes funding for the alternative engine, but a veto threat was conditioned on whether it would disrupt the $300 billion F-35 program.

Pennsylvania Democrat John P. Murtha , chairman of the House Defense Appropriations Subcommittee, predicted that funding for the GE alternative engine would be included in the conference agreement and would not disrupt the F-35 program.

In October, President Obama signed a fiscal 2010 defense policy measure (PL 111-84) that authorizes $560 million for the alternative engine, despite a similar veto threat.

Tough Timing

GE officials and congressional aides who favor competition for the F-35 engine said the engine problems couldn’t have come at a more politically charged time, as negotiators put the finishing touches on the fiscal 2010 spending bill.

“I don’t think this changes everything; competition has always been the principle here,” a senior House Appropriations Committee aide said.

Those who favor two engines argue that competition improves the product over the life of the program, could save money and gives the multiservice fighter program more options should an engine have a problem that grounds it for any period of time. Those who favor a single-engine approach say it is too costly in the short term to develop both engines, and they dispute whether competition would save enough money to recoup the investment over the life of the program.

Lieberman, a staunch supporter of a single-engine approach, noted in his letter that the F-35 Joint Program Office had not responded to “multiple requests through my staff” about the GE engine failure.

Lieberman also demanded an update on the total planned and executed hours of testing for the F136 engine. Industry officials and Lieberman have expressed concerns that the testing delays could affect scheduled delivery of engines, as well as cost.