The United States Navy and Marine Corps have followed the Air Force’s lead in grounding their fleets of F-35s over concerns of explosive cartridges in the Martin-Baker ejection seats.

The issues experienced with the U.S. aircraft are with cartridge actuated devices (CAD) in Martin-Baker ejection seats. The CADs “initiate a series of automatic functions when aircrew pull the ejection handle to safely egress the aircraft and deploy the aircrews’ parachute,” according to the Navy, meaning pilots are at risk of not being able to evacuate the aircraft in an emergency. A similar grounding happened this week in Europe with the Eurofighter in several nations’ air forces.

According to an Air Force Spikesperson:

“Following initial inspections of a small number of F-35 aircraft and discussions with our logistics professionals and Air Combat Command, the [Air Education & Training Command AETC] commander joined the ACC Commander in directing an operational pause beginning Friday, July 29 to allow our logistics team to further analyze the issue and expedite the inspection process,” Capt. Lauren M. Woods said. “Based on the results of these inspections and in conjunction with ACC, the lead command for F-35, AETC will make a decision regarding continued operations.”

The Air Force has a fleet of about 340 F-35s, with the Navy and Marine Corps having about 300. “The Department of the Navy leadership decided to inspect all Navy and Marine Corps F-35s jets in compliance with the 90-day [inspection order],” F-35 JPO deputy spokesman Chief Petty Officer Matthew Olay said. “The Department of the Navy decided to compress the 90-day inspection timeline to having each aircraft inspected prior to its next flight. All inspections are being conducted in an expedited manner with a high priority.”