Flights of Lockheed Martin Corp.'s F-35 will be allowed to resume, the Defense Department said, ending a suspension of the Fort Worth-produced fleet that followed the discovery of a cracked engine blade in one of the stealth jets.
The affected engine had been subjected to "prolonged exposure to high levels of heat and other operational stresses" in testing, the Pentagon's F-35 office said in a statement.Inspections of other F-35s found no "cracks or signs of similar engine stress," and no redesign will be needed for the engines built by the Pratt & Whitney unit of United Technologies Corp., according to the statement.The F-35, the Pentagon's most expensive weapons program, has been plagued by a costly redesign, bulkhead cracks, excessive weight and delays in software that have helped put it seven years behind schedule.The cost of the program's 2,443 aircraft is estimated at $395.7 billion, a 70 percent increase since 2001.The flight suspension was ordered Feb. 22 after a routine engine inspection revealed a crack in a turbine blade on a test aircraft at Edwards Air Force Base in California. The grounding was undertaken as a "precautionary measure," the Pentagon's F-35 office said that day in a statement.The decision to end the suspension came after Pratt & Whitney recommended that flight operations be restored.Big orderLockheed Martin, the world's largest defense contractor, was informed earlier Thursday that it will receive a $333.7 million down payment to buy initial parts and materials for an eighth batch of F-35s. The Pentagon locked in the funds hours before automatic U.S. budget cuts were set to take effect.The action exempts the funding from across-the-board spending reductions, known as sequestration, that begin today. Pentagon officials have said contracts with obligated dollars won't be cut or terminated.The eighth contract calls for 35 jets, including four for the United Kingdom and two for Norway, according to a Pentagon statement.The Defense Department sheltered the F-35 funding from spending cuts even as officials warn that they will have to impose furloughs on civilian workers.Lockheed said in a statement that it "will continue to drive down costs" for the F-35.Have more to add? News tip? Tell us

