A report that a lone air traffic controller may have been asleep at one of the nation's major airports has drawn the attention of federal authorities and prompted America's transportation secretary to order more than one controller staff the airport's midnight shift.
Pilots in two commercial planes reported that as they approached the nation's capital Tuesday night, they were unable to contact air traffic control at Reagan National Airport before landing.
The American Airlines and United Airlines planes both had been in contact with regional air traffic controllers before being handed off to Reagan National. The pilots landed their planes safely but without help from the airport tower.
"Tower is apparently unmanned. Called on the phone. Nobody answering, so aircraft went in just as an uncontrolled airport," one pilot said according to recorded radio communication.
In another transmission, a pilot said that "it's happened before."
One aviation official told The Associated Press that the single controller scheduled to be on duty at the time had fallen asleep. Others have speculated that the controller may have been locked out of the tower.
This evening, Transportation Secretary Ray LaHood weighed in.
"Today I directed the FAA to place two air traffic controllers at Ronald Reagan Washington National airport's control tower on the midnight shift," he said in a written statement. "It is not acceptable to have just one controller in the tower managing air traffic in this critical air space. I have also asked FAA Administrator Randy Babbitt to study staffing levels at other airports around the country."
The FAA, the agency responsible for air traffic control, said today it is investigating the report and promised that it is "looking into staffing issues and whether existing procedures were followed appropriate."
The NTSB added that it is looking into the incident, which occurred between midnight and 12:30 a.m.
One pilot contacted by ABC News today said that while the incident was unusual, it would not have presented a danger to passengers, because pilots are trained to land without air traffic control.
While Reagan National is staffed with multiple air traffic controllers during the day, the overnight shift is managed by just one controller, because there are no departures overnight and few arrivals. The airport serves some 18 million passengers a year.
ABC's Matt Hosford and The Associated Press contributed to this report.