Pentagon Grounds F-35 Fighter Jet Fleet Following Crash

WASHINGTON — The Pentagon grounded its fleet of F-35 strike fighter jets on Thursday, weeks after one crashed in South Carolina in another setback for the advanced aircraft that has long been mired in mechanical problems.

The decision to halt F-35 flights stems from what the military suspects is a faulty fuel tube installed in some of the aircraft, according to a Pentagon statement. Some of the jets are already aboard a Navy ship and have carried out airstrikes in Afghanistan.

Israel, Britain and other allies who have bought the F-35 from American manufacturers must also ground and inspect the fuel tubes in the jets, the statement said. There are roughly 220 F-35s in the U.S. inventory, purchased from defense contractor Lockheed Martin.

In the investigation of the F-35 crash near Beaufort, South Carolina, military officials gathered “initial data” that pointed to problems with the fuel tubes — and ultimately could have contributed to the Sept. 28 accident.

One military official familiar with the investigation said the fuel tube has been a recurring concern with the F-35 fleet. The official said investigators were also focused on a potential fault with a spinning blade in the aircraft that is supposed to stop debris from flying into the engine.

The official, who spoke on condition of anonymity to discuss the ongoing investigation, said the Marine pilot involved in the crash had been flying back to Marine Corps Air Station Beaufort after the aircraft had begun to malfunction. The pilot ejected safely, roughly 5 miles from the airfield.

Though the F-35 had previously experienced other problems, such as complications with pilots’ helmets and with engine fires, last month’s incident marked the first time the jet had crashed in its 17-year history.

“The primary goal following any mishap is the prevention of future incidents,” Joe Dellavedova, the public affairs director for the office that oversees the F-35 program, said in the Pentagon statement. “We will take every measure to ensure safe operations while we deliver, sustain and modernize the F-35 for the warfighter and our defense partners.”

Dellavedova said that inspections of the fuel tubes are expected to be completed within the next two days. Jets with tubes that are cleared will continue flying.

In 2016, weeks after the Pentagon said that the F-35 was ready for some combat operations, top officials raised concerns, writing in a memo that the jet might be “not effective and not suitable across the required mission areas and against currently fielded threats” as currently configured.

The F-35 has often been called one of the most expensive weapons programs in history; each jet costs between $80 million and just over $100 million. It costs roughly $50,000 each hour to fly the aircraft, which is capable of avoiding enemy radar and uses a highly advanced software system.

By contrast, some of the U.S. military’s older jets cost around $10,000 per hour to fly.