Pentagon grounds 24 F-35s

The U.S. military has grounded roughly 24 F-35 joint strike fighters with higher flight hours, citing new fuel system inspections needed after the entire fleet was grounded earlier this month.

The F-35 Joint Program Office said on Thursday that it found two new parts needing inspection on older models of the fifth-generation jet. The Pentagon in early October grounded all versions of the Lockheed Martin-made aircraft to examine the fuel tubes within the engines, made separately by Pratt & Whitney.

{mosads}“The joint government and industry technical team has completed their assessment of the fuel supply tubes within the Pratt & Whitney engine on F-35 aircraft,” the office said in a statement.

“In addition to the previously identified failed tube, the analysis has identified two additional fuel supply tubes that require inspection.”

The F-35 JPO declined to say how many jets are grounded.

Only a couple dozen F-35Bs — the Marine Corps variant — would be kept out of the skies for the new analysis, according to Defense News and Marine Corps Times, the first outlets to report on the inspections.

The outlets also reported that the two additional tubes are made by the same supplier as the tube that first caused the fleet-wide grounding.

The F-35 office stressed that the two fuel tubes have not failed, and that “engineering data collected during the ongoing investigation established the requirement for a time-phased inspection based on engine flight hours.”  

“The inspection maintains F-35 fleet safety standards as older engines may require fuel tube replacement. The procedure to inspect and replace can be done by flightline maintenance without removing the engine.”

F-35s that have not reached the flight hours threshold are still in operation, the office added.

Lockheed Martin referred questions to the JPO and to Pratt & Whitney, but noted that they continue to work with the two “to minimize impact to the fleet.”

“Pratt and Whitney builds the F135 engine and contracts directly with the F-35 Joint Program Office — and they can best address technical questions related to the engine,” the company said in a statement.

The Pentagon first announced it had grounded all F-35s on Oct. 11 after a fuel tube in the F-35 engines were suspected to have caused an F-35B crash on Sept. 28, near the Marine Corps Air Station Beaufort, S.C.

The pilot safely ejected from the fighter in that crash.