A US Air Force F-35 pilot spent nearly an hour on a mid-air conference call with Lockheed Martin engineers in a bid to fix a malfunction before ejecting from the jet, which later crashed in Alaska. Investigators found frozen hydraulic fluid caused the landing gear to fail, leaving the aircraft uncontrollable. The pilot survived with minor injuries, but the $200 million loss adds to growing concerns about the F-35 programme, its cost, safety record, and reliance on global supply chains.