"Today Lockheed Martin and Air Force aircraft maintenance teams completed repairs on the last of 13 F-35As requiring modifications to avionics coolant tubes inside aircraft fuel tanks, and all affected F-35As have returned to normal flying operations," Defense News quoted a statement on Friday by Air Force spokesman Capt. Mark Graff.
Graff noted that two jets at a Norwegian base were back in action as well.
Flight operations for the beleaguered joint-strike fighter program were suspended after the US Air Force announced that insulation inside the aircraft’s fuel tanks had begun to disintegrate. Initially, 15 operational F-35s were affected, while 42 additional airplanes still in production were found to have faulty insulation as well.
Lockheed Martin first began repairs with Air Force maintenance workers in early October, and the F-35s were returned to service after having holes cut into their wings to remove the defective insulation.
Greg Ulmer, VP of Lockheed’s F-35 program, said that all planes should be back online by the end of 2017. The fifth-generation fighter has been plagued by problems from the beginning. Militaries have been beset by rising costs, software delays, lightning protection, issues with flight control and even jets catching on fire.
At a March hearing, Pentagon representative Michael Gilmore remarked that the F-35 had 931 documented deficiencies, 158 of which were potentially lethal, had "many unresolved significant deficiencies.” and said the jet was “immature and provides limited combat capability."