The Metropolitan Airports Commission has identified the two Northwest pilots who overflew the Minneapolis-St. Paul airport by 150 miles Wednesday evening.
An incident report filed by the airport police identified the pilots as Timothy Bryan Cheney and first officer Richard Irwin Cole. The two men could not be immediately reached for comment.
According to the report, the pilots were "cooperative, apologetic and appreciative." The pilots voluntarily submitted to a breathalyzer test, which showed that neither pilot had been consuming alcohol.
The report filed by an airport police officer states, in part:
"When the airport taxied to the gate I was able to see two white males in the seats of the flight crew, both were wearing uniforms consistent with Delta flight crew. When the aircraft had stopped, the male seated in the pilot seat turned, looked at me and gave me two thumbs up and shook his head, indicating all was okay."
In a conversation with airport officers, Cheney "indicated they had become involved in conversation and had not heard radio communications," the report said. Cole verified Cheney's statement, according to the report.
The lead flight attendant told airport police that she was unaware of any incident during the flight. The pilots also told police that there had been no involvement from anyone in the cabin.
Cheney is from Gig Harbor, Wash., and Cole is from Salem, Ore., according to Federal Aviation Administration records.
The two are not expected to be charged by the airport police, according to MAC spokesman Patrick Hogan, and the investigation is now being led by the FBI.
Flight 188's pilots were out of touch with air traffic controllers for over an hour Wednesday night, flying past their Minneapolis destination at 37,000 feet. The pilots said they were distracted by a heated discussion of airline policy.
Investigators for the National Transportation Safety Board may have a hard time confirming that. It's likely the voice recorder captured only the last 30 minutes of the flight -- much of that time after pilots had realized their error and turned the plane back.
Newer records are two hours long.
Officials said air traffic controllers, other pilots and even a flight attendant on an intercom tried desperately to talk to the two pilots after they overshot the Twin Cities airport.
The airport police report said controllers also tried to contact the pilots by radio, data message and cell phone.
"[It was] unbelievable to me that they weren't paying attention."
Unable to raise Flight 188, police and FBI agents on the ground were preparing for the worst, while the North American Aerospace Defense Command, or NORAD, put fighter jets on alert at two locations as the drama unfolded.
NORAD spokesman Michael Kucharek said the planes had not yet departed by the time the FAA regained contact with the pilots.
Kucharek declined to say when NORAD learned of the wayward flight or when they created a response plan.
Pilots from two other planes in the vicinity were finally able to reach the pilots using a different radio frequency, a controllers union spokesman said.
A flight attendant in the cabin also was able to contact them by intercom, said a source close to the investigation who wasn't authorized to talk publicly and spoke on condition of anonymity.
By that time, the Airbus A320 was over Eau Claire, Wis., and the pilots had been out of communication with air traffic controllers for over an hour. They turned back and landed safely in Minneapolis, Minn., the plane's scheduled destination.
Although the pilots said they were distracted because of their intense conversation, there is speculation that the two of them might have fallen asleep.
Investigators don't know yet whether that was the case, but fatigue and cockpit distraction will be looked into, NTSB spokesman Keith Holloway said Friday.
They had hoped the plane's cockpit voice and flight data recorders would shed some light on the situation, but it appears they may not be very useful.
Investigators probably will not interview the pilots until next week, he said. The pilots have been suspended from flying by Delta Air Lines, which acquired Northwest last year, while the airline also investigates.
Bill Voss, president of the Flight Safety Foundation in Alexandria, Va., said that, regardless of whether the pilots fell asleep or were arguing, he expects both of the pilots will be fired.
"It doesn't matter much which one of those you chose," he said. "They're both pretty bad situations you'd have to own up to."
The pilots' explanation that they were distracted by shop talk "just doesn't make any sense," Voss said. "The pilots are saying they were involved in a heated conversation. Well, that was a very long conversation."
The plane, en route from San Diego with 144 passengers and a crew of five, passed over Minneapolis just before 8 p.m. CDT. Contact with controllers wasn't established until 14 minutes later, NTSB said.
Air traffic controllers in Denver had been in contact with the pilots as they flew over the Rockies, FAA spokeswoman Laura Brown said.
But as the plane got closer to Minneapolis, she said, "the Denver center tried to contact the flight but couldn't get anyone." That was just before 8 p.m.
Denver controllers notified their counterparts in Minneapolis, who also tried to reach the crew without success, Brown said.
Controllers suspected that Flight 188's radio may still have been tuned to a frequency used by Denver controllers even though the plane had flown beyond the reach of that region's controllers, said Doug Church, a spokesman for the National Air Traffic Controllers Union.
Controllers worked throughout the incident with the pilots of other planes, asking them to try to raise Flight 188 using the Denver frequency, he said.
That was unsuccessful until two pilots working with Minneapolis controllers finally got through just before the plane turned around, Church said. Minneapolis controllers don't have the capability of using the Denver frequency, but pilots do, he said.
After re-establishing contact with the plane, controllers asked the pilot in charge to execute a series of turns to show he was in control of the aircraft, Church said.
"Controllers have a heightened sense of vigilance when we're not able to talk to an aircraft. That's the reality post-9/11," he said.
Passenger Lonnie Heidtke said he didn't notice anything unusual before the landing except that the plane was late.
The flight attendants "did say there was a delay and we'd have to orbit or something to that effect before we got back. They really didn't say we overflew Minneapolis. ... They implied it was just a business-as-usual delay," said Heidtke, a consultant with a supercomputer consulting company based in Bloomington, Minn.
Once on the ground, the plane was met by police and FBI agents. Passengers retrieving their luggage from overhead bins were asked by flight attendants sit down, Heidtke said.
An airport police officer and a couple other people came on board and stood at the cockpit door, talking to the pilots, he said.
"I did jokingly call my wife and say, 'This is the first time I've seen the police meet the plane. Maybe they're going to arrest the pilots for being so late.' Maybe I was right," Heidtke said.
Passenger Bach Packer said the flight left San Diego late and flew through a storm on the way. Like Heidtke, Packer said that police and other officials immediately boarded the plane when it landed.
Packer said the police and other officials then searched the cockpit and removed what appeared to be a hard plastic box. He said flight attendants looked scared, and the pilots remained in their seats facing forward while the passengers exited.
"It was strange," Packer said. "When you were deplaning, it felt really, really odd."
Andrea Allmon, who had been traveling from San Diego, Calif., on business, didn't know anything was amiss.
"Everybody got up to get their luggage, and the plane was swarmed by police as we were getting our bags down from the overhead bins," she said.
She said they were kept on the plane briefly while police talked to the crew. Allmon said she was "horrified" to learn what had happened and it was "unbelievable to me that they weren't paying attention. Just not paying attention."
The FAA is updating rules governing how many hours commercial pilots may fly and remain on duty. The NTSB also cautioned government agencies this week about the risks of sleep apnea contributing to transportation accidents.
January 2008, pilots fell asleep for at least 18 minutes during a midmorning flight from Honolulu to Hilo, Hawaii. The plane passed its destination and was heading out over open ocean before controllers raised the pilots. The captain was later diagnosed with sleep apnea.
U.S. Sen. Al Franken of Minnesota called for an expedited investigation into the incident Friday, in a letter sent to Ray LaHood, Secretary of the U.S. Department of Transportation.
"Unfortunately, this was not an isolated incident," the letter states. "Yesterday's overshoot, the February 2008 overshoot in Hawaii, and the nine-hour Rochester tarmac delay in August all highlight the critical need to revamp our national air traffic control system."
Franken also asked for a review of regulations that require pilots to refrain from idle conversation during flights.
(The Associated Press contributed to this report)