The US Air Force has grounded 10 of its F-35 Joint Strike Fighters.
The decision was taken due to the discovery of peeling and crumbling insulation in avionics cooling lines inside the fuel tanks.
The faulty cooling lines affected a total of 57 aircraft. Only 15 of those planes had been fielded with the remainder still on the production line and will be fixed there.
The plane’s manufacturer, Lockheed Martin, has delivered 108 F-35As. The Air Force plans to buy 1,763 of the jets.
The F-35 jet has been described as the most expensive weapons system in history with a programme cost estimated to be $400 billion.