Two US pilots who overshot their destination by 150 miles - sparking hijack fears - say they lost track of time while checking work rotas on their laptops.
Captain Timothy Cheney and first officer Richard Cole were distracted for more than an hour as they cruised in the dark at 37,000ft in a Northwest Airlines jet carrying 144 passengers. Air traffic controllers in two states and pilots of other planes tried to attract their attention to warn them they had flown past Minneapolis airport.
On the ground, officials feared the aircraft had been hijacked and alerted the military, which put two jets on standby. US investigators who interviewed the pair said they were not tired during the evening flight from San Diego - scotching rumours they had fallen asleep.
Instead the National Transportation Safety Board (NTSB) said "they lost track of time" while using their personal laptops. "The pilots said there was a concentrated period of discussion where they did not monitor the airplane or calls from (air traffic controllers) even though both stated they heard conversation on the radio," it added.
Neither pilot was aware the plane had over run the airport until a flight attendant asked what time they were due to arrive, the NTSB said. Captain Cheney, 53, checked his flight display data and, realising the mistake, contacted controllers for permission to turn around.
Delta Airlines, which owns Northwest, said in a statement the use of laptops or "engaging in activity unrelated to" flying violates company policy. It has suspended the pilots as it continues its investigation.