The U.S. Air Force has grounded 15 F-35A Joint Strike Fighters and paused production on 42 more blaming “improper manufacturing processes.”
The Air Force declared the F-35A ready for combat on Aug. 2, 2016. Following the grounding, however, there is no timeline for the aircraft to return to combat readiness.
Navy and Marine Corps variations of the fighter jet are not affected by the most recent grounding.
According to a statement from the Air Force, poorly built insulation material is “crumbling” into fuel tanks.
Problems with material breaking off into fuel tank cooling lines “was discovered during depot modification of an F-35A and affects a total of 57 aircraft,” Air Force spokeswoman Ann Stefanek said Sept. 16.
Of the 57, 15 had been deployed for flight out of bases in Arizona, Nevada and Utah, according to the Air Force, with 13 of those belonging to the US and two to Norway. The remaining 42 are in production.
Air Force maintenance, the F-35 Joint Program Office and Lockheed Martin are working on a solution at Hill Air Force Base in Utah, Reuters reported.
“The Air Force is also working with units to mitigate the impact on operations, training, and readiness,” the Air Force spokeswoman said.
In a statement to Aviation Week, the Norwegian government stressed that this was not a design flaw, but a quality matter. A supplier had used “improper materials and improper sealing techniques.”
The F-35 Joint Program Office told Aviation Week that the materials provider used “improper manufacturing processes” and “nonconforming material,” which was incompatible with fuel for the tubing insulation.
“This appears to have been an isolated incident,” Major General Morten Klever, director of the Norwegian F-35 Program Office, told Aviation Week. “We expect this to be resolved by the time we receive the next aircraft currently in production.”
“The F-35 JPO and Lockheed Martin have a proven track record of solving issues and we’re confident we’ll continue to do so,” the Joint Program Office said, according to Aviation Week. “The Government and Industry team is now developing repair procedures to remedy the problem and return the affected aircraft back to safe flying operations.”