One of the two Northwest Airlines pilots who were out of contact with air traffic controllers for more than an hour Wednesday while they overshot their destination denies suggestions that they fell asleep.
"I can assure you none of us was asleep," First Officer Richard I. Cole told ABC News.
He declined to comment further but said, "I am not doing very good."
This evening, the Federal Aviation Administration released a brief statement suggesting the pilots on the San Diego-to-Minneapolis flight could face serious consequences as the agency investigates.
"The FAA has sent letters of investigation to the two pilots involved in the recent Northwest Airlines overflight of Minneapolis," the statement said. "Depending on the outcome of our investigation, this action could lead to emergency suspension or revocation" of their licenses.
Cole and fellow pilot Timothy B. Cheney told the FBI and airport police they lost track of time and got distracted because they were in a heated discussion over airline policy, the FAA has said. The pilots told police "they had become involved in conversation and had not heard radio communications."
The pilots of the Airbus A320 were out of contact with air traffic controllers who frantically tried to reach the plane for 1 hour and 18 minutes.
The pilots -- who stayed at 37,000 feet and overshot the airport by 150 miles -- were finally reached at 8:14 p.m., but the jet with 147 passengers did not land at Minneapolis-Saint Paul International Airport until 9:05 p.m.
The cockpit voice recorder on the flight is only a 30-minute recorder, resetting on a loop after that period, according to the National Transportation Safety Board. That means that unless the pilots stopped the recorder, the only sounds captured from the flight would be the last half hour, when the pilots were back in communications with air traffic controllers.
Newer flight recorders tape two hours of sounds before resetting.
"From the point of course reversal to touchdown was about 50 minutes," said Daniel Baker, founder and CEO of flight-tracking company FlightAware.com.
Since Delta and Northwest merged a year ago, many pilots have been angered over job seniority and the routes they fly, perhaps a factor in a cockpit discussion.
Airport police who met the plane at the plane at the gate asked the pilots to submit to a alcohol breath test. Cheney and Cole both voluntarily agreed and the tests showed no traces of alcohol, according to the police report.
It appears that there were no bells or whistles or any other audible sound to alert the pilots that they had passed their last flight marker, so-called "way points."
Instead, there would be a message on screens that sit on the pedestal between the two pilots. That message would have said "flight plan discontinuity."
Federal counterterrorism agencies treated the stray jetliner as a serious threat. Fighter jets were placed on alert, though not put in the sky.
Authorities began to immediately look at the flight manifest and crew and checked to see if there were air marshals onboard. The National Counterterrorism Center was notified and the Minneapolis Joint Terrorism Task Force was put on notice.