The Pentagon has announced that it is grounding its complete fleet of F-35s following preliminary investigations of a recent crash, pointing to the possibility of a widespread problem with the advanced fighter’s fuel tubes, The Marine Corps Time has reported.

On 28 September, single-seat Lockheed Martin F-35B Lightning II with Marine Corps training squadron VMFAT-501 crashed on a small island just miles from Marine Corps Air Station Beaufort. The pilot, a US Marine, however, escaped unhurt and was ejected safely.

“The US Services and international partners have temporarily suspended F-35 flight operations while the enterprise conducts a fleet-wide inspection of a fuel tube within the engine on all F-35 aircraft,” the F-35 Joint Program Office announced in a statement released on Thursday morning.

The global fleet of F-35s — including Marine Corps, Air Force and Navy variants — will stay on the ground to enable inspectors to examine the airplanes’ engines.

Close to 320 jets would undergo inspections over the next 48 hours to check fuel tubes in engines that are made by Pratt & Whitney, a unit of United TechnologiesCorp.

The F-35 joint strike fighter is reportedly the most expensive program in the Pentagon’s history. The aircraft program is projected to cost about $1 trillion to develop, produce, field and sustain over its lifetime.

The F-35B has a single Pratt & Whitney engine and a lift fan made by Rolls-Royce that allows it to take off and land vertically.

A Lockheed Martin spokesperson said, “We are actively partnering with the Pentagon’s F-35 Joint Program Office, our global customers and Pratt & Whitney to support the resolution of this issue and limit disruption to the fleet.”

The US military has so far purchased 245 aircraft from Lockheed Martin. The Air Force has 156, the Marine Corps has 61 and the Navy has 28.

Britain, Italy, Australia, Israel and Norway are also flying the planes.