F-35 conducts routine training aboard USS Abraham Lincoln

An F-35C, assigned to Marine Wing Fighter Attack Squadron (VMFA) 314, launches from the flight deck of the aircraft carrier USS Abraham Lincoln (CVN 72). (US Marine Corps/1stLt. Charles Allen)

Editor’s note: The original version of this story ran under the headline “Navy, Marines join Air Force in grounding F-35s for ejection seat inspections,” with content that reflected that headline. That was based on information provided to Breaking Defense by the F-35 Joint Program Office, which indicated that ongoing plane inspections were being conducted around the CAD issue. After publication, the Navy and Marines contacted Breaking Defense stating that their fleets have largely completed their inspections, contrary to the statement from the JPO. This story has been updated to reflect the statements of the JPO, Navy and Marines.

WASHINGTON: The US Navy and Marine Corps have quietly been inspecting their F-35 fleets for some time to determine if they are impacted by safety concerns stemming from potentially defective parts on ejection seats, with the Navy saying it completed inspections on July 26.

The issue with the Martin-Baker made ejection seat stems from cartridge actuated devices (CADs) — explosive cartridges used inside ejection seats to help propel the seat out of an aircraft during an emergency. The Navy disclosed earlier this week that certain production lots of CADs used in Martin-Baker ejection seats have been identified by the company as being defective and needing replacement, but had not previously said that the F-35 fleet was considered at potential risk.

Concerns that the ejection seat could imperil pilots have already grounded a number of other naval aviation fleets, as well as the majority of the US Air Force’s F-35 models, as first reported Friday by Breaking Defense.

Throughout Friday, Breaking Defense was directed by multiple naval offices to talk to the JPO for comment on what, if any, impact the CAD situation was having on the F-35 fleet.

“The Navy is inspecting the [ejection seats] in the Department of the Navy F-35 fleet. Those inspections have already begun,” F-35 JPO deputy spokesman Chief Petty Officer Matthew Olay said in a Friday afternoon response to questions from Breaking Defense about the status of the Navy and Marine jets. “The Navy’s F-35B and C fleet is currently executing CAD verification procedures in accordance with an F-35 JPO directive. Once complete with the CAD inspection, aircraft will be cleared to fly.”

According to Olay, the JPO had previously issued an order to inspect all F-35s in a 90 day window. “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.” International F-35 customers have also been made aware of CAD issue, he said.

However, late on Friday, Cmdr. Zachary Harrell, spokesperson for the Commander of Naval Air Forces, issued a statement saying those statements did not reflect the current situation with its F-35 fleet.

“U.S. Navy and Marine Corps F-35C Lighting II operations are not impacted by the potential defect in the cartridge activated devices. F-35Cs are not grounded,” he said, adding that “A small number of CADs in F-35Cs were determined to be potentially affected; those CADs were immediately replaced and those aircraft have been returned to operational status.”

“CAD verification procedures were done in conjunction with the inspections that were completed by Aug. 26, and all F-35Cs have been cleared for normal operations,” Harrell added.

Shortly after, Maj. Jay Hernandez, a spokesman for Marine Corps aviation, issued a statement saying, “Out of an abundance of caution, the Marine Corps conducted maintenance inspections on all F-35B/C Lighting II ejection seat cartridge actuating devices even earlier in the maintenance cycle than recommended by the OEM, and chose to inspect the ejection seat cartridge actuating devices before their next flight instead of the 90 day window engineers had approved.

“Currently, Marine Corps F-35Bs are not grounded, and over 90 percent of the inspections on Marine Corps ejection seat cartridge actuating devices are now complete.”

Earlier today, the Air Force’s Air Combat Command (ACC) and Air Education and Training Command (AETC) confirmed that it had temporarily suspended F-35 flight operations on July 29 so that the maintainers could inspect its jets and replace any defective cartridges. ACC and AETC own the lion’s share of the service’s F-35s used for training and operations, but other major commands such as United States Air Forces in Europe (USAFE) and Pacific Air Forces (PACAF) also field F-35 squadrons.

In a statement, Martin-Baker spokesman Steve Roberts said that “During a routine maintenance inspection at Hill AFB in April ’22, an anomaly was discovered with one of the Seat Cartridge Actuated Device (CAD) in the F-35 seat. This was quickly traced back to a gap in the manufacturing process which was addressed and changed. The F-35 Program introduced a one-time directive to inspect this CAD on all Seats in order to return the F-35 aircraft to flight.

“This issue was found to be unique to this particular CAD part number and unique to the F-35, Martin-Baker has been providing the primes and multiple Govt agencies with supporting data to prove that all other aircraft may be excluded. Outside the F-35, not a single anomaly has been discovered worldwide as a result of the forensic investigation which continues at pace”.

However, there are clearly concerns over the ongoing issue. Earlier this week, the Air Force’s Air Education and Training Command stated that it had temporarily grounded almost 300 training aircraft due to the CAD-supply issue, and the Navy separately acknowledged that it had grounded an unspecified number of its own trainers and combat aircraft.

Breaking Defense first reported the Navy groundings on Wednesday, and Air Force Times first reported the Air Force groundings on Thursday. The problem has also impacted the United Kingdom’s Eurofighter Typhoons and Red Arrow demonstration team, according to the Daily Express.