WASHINGTON (Reuters) - The leaders of the Senate Armed Services Committee on Monday blasted the Pentagon's decision to lift a "probation" imposed on the Marine Corps variant of the Lockheed Martin Corp F-35 fighter a year earlier than planned, saying the move appeared premature and was not vetted with Congress.
Senator Carl Levin, chairman of the Senate Armed Services Committee, and Senator John McCain, the top Republican on the panel, questioned the decision and lack of consultation in a strongly worded letter to Defense Secretary Leon Panetta.
Panetta threw his support behind the F-35B model and the entire $382 billion program - the Pentagon's most expensive arms program - last month during a carefully orchestrated visit to a Maryland military base where the warplanes are being tested.
A week later, he told reporters the Pentagon would further slow procurement of new F-35s to allow more time for development and testing.
The senators said it was unclear the Pentagon had ever clearly defined the specific criteria required by the fiscal 2012 defense authorization bill to determine when the F-35B would exit probation, since it offered the committee a "hastily-prepared report on the F-35B" only after Panetta's announcement.
"Your decision may have foregone a valuable opportunity to continue driving desired improvements" on the program, the two lawmakers wrote in the letter, which was released on Monday by McCain's office.
"We believe that every opportunity to focus Lockheed Martin's attention and disrupt 'business as usual' in this multibillion-dollar effort ... should be maximized," they said.
The senators asked Panetta to submit quick answers to 14 detailed questions about his decision to back the F-35B model, which takes off from shorter runways and lands like a helicopter.
They noted that Lockheed's contract with the Pentagon to build a fourth batch of F-35 fighter jets was only half complete, but was expected to exceed the contract's target cost of $3.46 billion by $245 million and that concurrency charges would add $237 million more to the program's cost. Concurrency costs refer to the cost of retrofitting already produced aircraft if problems occur during developmental testing.
They questioned how such a cost overrun favored removing the B-model from probation early, especially since half of the aircraft in the 32-plane contract were the B-model.
Levin and McCain also asked the Government Accountability Office, a congressional watchdog agency, to examine the status of the F-35 B model and any lingering development issues as part of its annual review of the F-35 program.
(Reporting By Andrea Shalal-Esa; editing by Andre Grenon)