Two pilots who allowed their passenger jet to overshoot its destination by 150 miles last week have told investigators that they lost concentration because they were using their laptop computers in the cockpit.
In an admission that will strike fear into the heart of frequent flyers everywhere, the men in charge of Northwest Airlines flight 188 from San Diego to Minneapolis revealed that they were operating the machines during a discussion about crew scheduling.
As a result, the plane, which was carrying 147 passengers, lost contact with air traffic control for over an hour. It had passed Minnesota and was drifting over Wisconsin at 37,000 feet before anyone on the flight deck noticed.
The National Transportation Safety Board, which is compiling a report into the incident, said both pilots vehemently denied speculation that they fell asleep, and instead insisted that they had simply "lost track of time" while working out their new work timetables.
"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," said the Board, after interviewing the pair for five hours on Sunday.
Homeland Security was closely tracking the Airbus A320 during the incident amid fears that it had been hijacked, and four National Guard jets were put on standby to shoot it down should it venture near to a major conurbation.
However the two pilots, who are both said to have been in the job for many years, only realised they had overshot their final destination when an air hostess knocked on the cockpit door and asked what the flight's estimated arrival time was.
Realising the extent of their mistake, the men immediately contacted air-traffic controllers for permission to turn around, saying during radio conversation that they had suffered "cockpit distraction". The plane then landed without further incident in Minneapolis.
They were both suspended from duty, pending the outcome of investigations said Delta Air Lines, which recently bought Northwest. Customers are unlikely to be reassured by the fact that the takeover in question is said to have led to the introduction of the new staffing rota that prompted the pilots to both get their laptops out.
Delta added in a written statement the use of laptops or "engaging in activity unrelated to" flying violates company policy. Both men could eventually be fired, a spokesman added.