The crash of a U.S. Marine Corps F-35B that temporarily grounded the entire fleet of next-generation jets in 2018 was caused by a manufacturing defect in a fuel tube made by a United Technologies subcontractor, according to congressional investigators.
The defect "caused an engine fuel tube to rupture during flight, resulting in a loss of power to the engine," the Government Accounting Office said last week in a report on major weapons systems that referred to the September crash in South Carolina. The Pentagon told the watchdog that it identified 117 aircraft — about 40 percent of the worldwide F-35 fleet at the time — with the same type of fuel tubes that had to be replaced.
The disclosure was the first official information about the crash since the Pentagon program office in late October issued a status statement while the Marine Corps was still conducting its investigation. United Technologies Corp.'s Pratt & Whitney unit "is fully responsible" for "the propulsion system and has the lead in working" the failure analyses, according to the statement at the time.