The National Safety Transport Board, the American air safety agency, has released its report into an incident which occured at Ronald Regan Airport during March 2011. The incident received wide media interest when it was reported an air traffic controller fell asleep requiring aircraft to land without a clearance.
The executive summary of the report states
Between approximately 0004 and 0028 local time, an air traffic control service interruption occurred at the Ronald Reagan Washington National Airport when two air carrier aircraft, a helicopter, an airport operations vehicle, and controllers at the Federal Aviation Administration's Potomac Terminal Radar Approach Control were unable to establish contact with the supervisory controller working alone in the control tower. Two air carrier aircraft landed during the period without tower contact. Postincident investigation revealed that the controller on duty had the necessary preconditions for the development of fatigue at the time of the event, specifically acute sleep loss in the 24 hours before the event and circadian disruption as a result of working the midnight shift.
The full copy of the report is available from Full narrative available .
Currently five Australian Air Traffic Control facilities have single person staffing during the midnight to dawn shift.