The Air Force on Friday ordered a temporary, but indefinite, pause in flight operations for 13 F-35As due to peeling and crumbling insulation in avionics cooling lines inside fuel tanks, according to a service statement.
The issue was discovered during depot modification of a F-35A and affects a total of 57 aircraft: 15 currently fielded, of which two belong to a partner nation. The 15 aircraft are 10 at Hill AFB, Utah; four at Luke AFB, Ariz.; and one at Nellis AFB, Nev. The pause also affects 42 production aircraft, 28 of which belong to the United States and partner nations and 14 foreign military sales (FMS) aircraft. Norway said the grounding affects two of its aircraft that have been delivered.
Engineers with the F-35 Joint Program Office (JPO), Lockheed Martin [LMT] and Hill maintenance airmen have conducted inspections of eight aircraft and are currently developing procedures to resolve, or mitigate, the issue before release of affected production aircraft to the field and the return of affected operational aircraft to flight operations. The Air Force is also working with units to mitigate the impact on operations, training and readiness.
Programmed flying training and other impacts will depend on the number and timing of aircraft returned to service. Subject matter experts are considering courses of action to mitigate these delays. The Air Force did not respond to a request for comment by press time Friday.
The F-35 is developed by Lockheed Martin with BAE Systems and Northrop Grumman [NOC].