US Air Force grounds F-35 fighter jet fleet to investigate faulty ejector seats, report says

• The US Air Force has grounded its fleet of F-35 jets over concerns about the ejector seats.
• Bloomberg reported that the issue involved the seats' explosive cartridges made by Martin-Baker.

The US Air Force has temporarily grounded its fleet of Lockheed Martin F-35 fighter amid concerns that the ejector may be faulty.

Bloomberg reported that a potentially faulty component in the mechanism that could endanger pilots in an emergency was being investigated.

Since Thursday, Air Force has grounded almost 300 jets, according to the report.

An Air Force spokeswoman, Alexi Worley, told Bloomberg the issue involved the explosive cartridges inside ejection seats that propel both the seat and the pilot from the jet.

Inspections of all the cartridges began on July 19 and all F-35 jets were grounded on July 29 to speed up the process.

The data gathered will be used to determine when operations can resume, she said.

The jets all have ejector seats made by Martin-Baker Aircraft.

Steve Roberts of Martin-Baker told Bloomberg only F-35s were affected. He confirmed an "anomaly" was found with one of the seat cartridge devices in the fighter in April. "This was quickly traced back to a gap in the manufacturing process which was addressed and changed."

"Outside the F-35, not a single anomaly has been discovered worldwide as a result of the forensic investigation which continues at pace," Roberts added.

The US Air Force has the world's largest F-35 fleet, with 348 jets. It says they have the most advanced sensor suite of any fighter.

The USAF and Martin-Baker did not immediately respond to Insider's request for comment.