Two airliners landed at Reagan National Airport near Washington without control tower clearance because the air traffic supervisor was asleep, safety and aviation officials said Wednesday.
The supervisor - the only controller scheduled for duty in the tower around midnight Tuesday when incident occurred - had fallen asleep, said an aviation official, who spoke on condition of anonymity to discuss the incident.
The National Transportation Safety Board is gathering information on the occurrence to decide whether to open a formal investigation, board spokesman Peter Knudson said.
The pilots of the two commercial planes were unable to reach the tower, but they were in communication with a regional air traffic control facility, Knudson said. That facility is in Warrenton, Va., about 40 miles from the airport.
Regional air traffic facilities handle aircraft within roughly a 50 mile radius of an airport, but landings, takeoffs and planes within about three miles of an airport are handled by controllers in the airport tower.