US Federal Aviation Administration officials are investigating a 25min air traffic control communications loss on 11 April at Seattle Tacoma (Sea-Tac) airport apparently caused by a controller leaving his duty station.
The FAA says the agency’s initial investigation shows the incident began when the sole controller staffing the tower left his duty station at around 03:15, leaving no one to monitor air traffic at the airport. Loss of communications was first reported when the pilot of a Delta Air Lines aircraft parked at gate S12 attempted to request relocation for maintenance, Sea-Tac director of operations Mike Ehl says.
One of the airport’s airfield operations specialists on duty overheard the transmission on an open radio transmission and tried to radio the control tower after no response was received, says Ehl.
A few minutes later, EVA Air flight 31, a Boeing 747-400 en route from New York Newark to Taipei requested clearance to land, he says. The airfield operations specialist, still unable to make contact with the tower, radioed a flight dispatcher who instructed the EVA 747 to make a go-around before landing.
Sea-Tac officials decided to close the airport until communications could be restored with the tower, says Ehl. Communications were restored at 03:40 when the missing controller returned to the tower, and the EVA 747 landed without incident. No other aircraft or airport operations were affected by the tower communications problem, says Ehl.
This was the first such incident involving a tower blackout at Sea-Tac, he adds. Agency officials have issued a new Sea-Tac-specific rule requiring two controllers to staff the tower during night shifts to prevent future incidents, says the FAA . Further action is expected as the FAA continues its investigation.
The US National Air Traffic Controllers Association declined to comment on the incident.
JOE SINGLETON / WASHINGTON, DC