Grounded F-35As Return to Flight

The Air Force on Nov. 18 finished repairs to 13 F-35As that had been grounded for about two months due to manufacturing defects in their fuel systems, giving the whole fleet a go for flight. The Air Force in September grounded the aircraft after it identified issues in the jets’ avionics coolant tubes inside the fuel tanks. The grounding impacted 13 USAF jets at Hill AFB, Utah; Luke AFB, Ariz.; and Nellis AFB, Nev. Two additional Royal Norwegian Air Force jets were impacted, along with 42 on the production line. The issue stemmed from a subcontractor improperly installing the lines, causing the Poly-Alpha-Olefin insulator to come off and potentially enter fuel lines, the Air Force said at the time. Technicians, beginning on Oct. 7, removed all non-compliant insulation material, according to a Friday statement. The grounding was “adopted out of an abundance of caution,” the Air Force said. The problem wasn’t a design flaw, but “a case of a supplier using improper material and improper sealing techniques for a part of the aircraft,” the service said in a statement.