The two pilots of the Northwest Airlines flight last week that missed its airport by 150 miles were apparently using their personal laptops to review scheduling as air traffic controllers repeatedly tried to reach them, the National Transportation Safety Board said.
The use of personal laptops in the cockpit violates airline policy, according to the NTSB, which issued a statement today on the incident after interviewing the pilots.
Neither pilot was aware of the airplane's position until a flight attendant, Barbara Logan, called about five minutes before they were scheduled to land and asked about their estimated time of arrival. It was only then that the captain realized they had passed the airport.
"I just called them and said when are we landing, and that was it," Logan told ABC News.
She said she didn't know anything was wrong, but just wanted to find out when the plane was landing. Logan said she didn't have a clue about what happened in the cockpit and the pilots didn't tell her.
Flight 188 had 144 passengers, two pilots and three flight attendants on board. It landed safely about an hour after its originally scheduled time.
The FAA is expected to either suspend or revoke the licenses of the pilots as early as Tuesday and it looks like Delta will move to fire the pilots.
Delta Monday afternoon said that using laptops or engaging in activity unrelated to the pilots' command of the aircraft during flight is against airline policy "and violations of that policy will result in termination."
"Nothing is more important to Delta than safety. We are going to continue to cooperate fully with the NTSB and the FAA in their investigations," Delta CEO Richard Anderson said in a statement.
For one hour and 18 minutes Wednesday night the pilots -- flying at 37,000 feet above sea level between San Diego and Minneapolis -- were radio silent as air traffic controllers at times tried to reach the cockpit.
As the event unfolded, concern was high among air traffic controllers, who repeatedly attempted to establish contact during the incident, using multiple methods, the air traffic controllers union told ABC News. Eventually, controllers asked other planes in the air to attempt to contact the Northwest plane, a method that the union said ultimately proved successful.
Federal counterterrorism agencies treated the stray jetliner as a serious threat. Fighter jets were placed on alert, though not put in the sky.
In separate interviews with the NTSB, Capt. Timothy B. Cheney and First Officer Richard I. Cole, told investigators they were in a "concentrated period of discussion" over a new monthly crew flight scheduling system in place as a result of the merger of Delta and Northwest. Both accessed and used his personal laptop computer while they discussed the airline crew flight scheduling procedure. Cole, who was more familiar with the procedure, was providing instruction to Cheney, the NTSB said.
The pilots said they lost track of time and were using cockpit speakers to listen to radio communications, not their headsets.
Initially, there was speculation that the pilots had fallen asleep in the cockpit. Both pilots dismissed that, saying they were not fatigued. Each had commuted to the flight, but they had a 19-hour layover in San Diego before arriving at work. They both told investigators that they did not doze during the flight and there was no heated argument.