Two commercial airline pilots allegedly fell asleep on a flight between Baltimore and Denver, with one pilot waking up to "frantic" calls from air traffic controllers warning them they were approaching the airport at twice the speed allowed.

The March 2004 event, which was discussed during a Congressional hearing on Oct. 31, 2007, was reported by the captain on the flight on NASA's Aviation Safety Reporting System, which allows crew members to anonymously document incidents.

Details of the "red eye," or late night/early morning flight, including the airline, flight number, or number of passengers aboard are not included in the reporting system. It did note the type of airplane, an Airbus A319, which are flown by Frontier Airlines and United Airlines.

United spokeswoman Megan McCarthy told the Rocky Mountain News, which first reported the incident, that United did not fly a "red eye" between the two cities at the time and it had no reports of that incident.

Frontier spokesman Joe Hodas told the newspaper the airline had a "red eye" flight on the schedule at the time but could not find a report of the incident.

US-based Federal Aviation Administration (FAA) officials did not immediately return a message left by the Associated Press after business hours.

"Last 45 mins of flt (flight) I fell asleep and so did the FO (first officer)," according to the narrative in the report.

The captain noted they were approaching a point where they were to begin their descent into Denver International Airport about 60 miles southeast of there at 35,000 feet, much higher than required, and at Mach .82, or 608 mph, instead of a required slower speed.

"I woke up, why I don't know, and heard frantic calls from ATC ... I answered ATC and abided by all instructions to get down. Woke FO (first officer) up."

He spiraled the jet down to a lower altitude as ordered, then landed "with no further incidents."

The pilot had been switched to three nights in a row of flying the overnight, eight-hour round trip.

While unable to find a report on the incident, Hodas said the airline has received similar reports in the past and have addressed them, noting that pilot fatigue is a bigger issue in the industry than the public realizes.

"We take safety very seriously and watch crew fatigue very closely," he said.

The company has a number of programs in place to prevent crew fatigue, including no-fault fatigue reporting in which a pilot who feels fatigued and is scheduled to fly can call and be relieved from flying.