A near collision of two airplanes at San Francisco International Airport was the fault of an air-traffic controller with a clean record and two decades of experience, federal officials investigating the incident said Monday.
On May 26, two planes came within 50 feet of each other on intersecting runways at SFO, after the air-traffic controller inadvertently gave permission for one plane to take off while another was landing, according to the National Transportation Safety Board, which announced Monday that it was investigating the incident.
According to NTSB spokesman Ted Lopatkiewicz, the controller — who has since been taken off duty pending further investigation — cleared SkyWest Flight 5741, an Embraer 120 turboprop airplane inbound from Modesto, to land, and then cleared Republic Airlines Flight 4912, another Embraer departing for Los Angeles.
When theSkyWest plane touched down, the Airport Movement Area Safety System kicked in, which alerts airplane crews and control towers to dangers on the runway. While the controller transmitted verbal instructions to the SkyWest plane to “hold, hold, hold,” the pilot and crew did not receive the call in time because of an inherent delay in the AMASS system, Lopatkiewicz said.
As a result, the SkyWest crew braked as hard as it could and came to a stop in the middle of the runway. The departing Republic Airlines plane, already traveling too fast to stop, had to initiate an immediate takeoff in order to clear the SkyWest plane by 50 feet or less.
While such incidents, to varying degrees, happen daily at airports nationwide, Lopatkiewicz said the severity of the incident at SFO prompted the agency to investigate.
NTSB does not investigate all runway incursions, or incidents risking collision, Lopatkiewicz said. However, the Federal Aviation Administration amdoes, and it interviewed the air-traffic controller, the pilot and the crew, and the communication data from the control tower.
The FAA, which has the authority to punish people deemed at fault in the incident, has been conducting an investigation into the matter for the last couple of weeks.
FAA spokesman Ian Gregor said the agency has not yet determined how serious the incident was.
Since 2001, runway incursions at SFO have been minor. On a letter-grade scale from A to D, where A is the most serious and D is the least serious, all incidents at SFO have been classified C or D, Gregor said.
Airport spokesman Mike McCarron said the airport is leaving the matter to the federal officials. NTSB does not levy punishments, but rather makes recommendations to the FAA for safety improvements.
“We take all recommendations from the NTSB very seriously,” Gregor said.