Pentagon acquisition chief Frank Kendall told lawmakers that early evidence suggests a recent F-35 engine failure was a single-engine issue, not a systemic problem–but he made clear the Defense Department needs to go through its full investigation and safety certification process before allowing the planes to fly again.

The undersecretary of defense for acquisition, technology and logistics told the House Armed Services Committee Thursday at an acquisition reform hearing that DoD has inspected all the engines of in-service Joint Strike Fighters after a F-35A caught fire during takeoff on June 23 and the entire fleet was subsequently grounded.

An F-35A. Photo: U.S. Air Force
An F-35A, like the one pictured above, caught fire while taking off at Eglin Air Force Base in Florida. The Air Force, followed by the Navy and Marine Corps, grounded the fleet pending an investigation. Pentagon acquisition chief Frank Kendall said Thursday that early evidence suggests there are no systemic problems in the fleet, but he would not comment on when the Pentagon’s grounding orders may be lifted. Photo: U.S. Air Force

“We have not found, as far as I know, anything that would suggest the type of problem that we think caused this failure,” he said. “We’re examining the actual engine that did fail, the parts of it we have, to try to determine what caused the failure.”

Kendall stressed multiple times that “I don’t want to get ahead of the safety and evaluation process,” noting that “as a political appointee, [I] don’t want to get involved or influence the safety process the safety professionals and the air worthiness professionals need to conduct.” But he added, “what I know now–I will go this far –there’s a growing body of evidence that this may have been an individual situation, not a systemic one. But we don’t know that for certain at this point in time.”

After the hearing, Kendall added that the safety professionals would like to understand a root cause of the engine failure before putting the planes back in the sky, but he would not comment on how long that could take and when the flight ban may be lifted.

In what could be a big hit for DoD, it is unlikely one of the Marine Corps’ F-35Bs will fly this weekend at the Royal International Air Tattoo (RIAT) in the United Kingdom, Marine spokesman Capt. Richard Ulsh said Thursday. Ulsh said DoD was still planning on debuting the jet in England later this month, likely referring to the Farnborough Air Show scheduled for next week.

DoD’s fleet of F-35s remained grounded Thursday, with the Air Force’s no-fly streak for F-35As reaching 17 days. An update from the Navy on its fleet of F-35Cs is expected Friday. An engine issue is suspected. Pratt & Whitney, a division of United Technologies Corp. [UTX], develops the F135 engine for the F-35.