An FAA spokesperson tells ABC7 News that they never lost track of the planes, but that rather, it was a telecommunications line that feeds information like speed and altitude that went down.
A backup system did not work for more than a minute after the outage. It happened at 10:05 a.m. at the Northern California Terminal Radar Approach Control Center in Tuolomne County which covers the arrivals and departures out of San Francisco, Oakland and San Jose.
The FAA declared an air traffic control alert. Planes in the air and on the ground were held. Air traffic controllers could still see the blips representing planes on radar, but no flight information.
The FAA says they got everything back except flight identifiers like airline and flight numbers after about a minute. The loss of identifiers lasted about 20 minutes before the FAA declared the radar was functionally acceptable. There were no reports of any close calls.
ABC7 aviation analyst Ron Wilson says on days like this, pilots will rely less on their instruments and more on their own eyes.
"Those pilots are looking out the windows all the time, more so than they're looking at their instruments under these conditions because they want to visually see that they are away from other airplanes," says Wilson.
Wilson alsy says problems like this happen more often than you may think because of outdated equipment used by the FAA.
As for Saturday's problem, air traffic controllers still had to manually upload flight data from the radar control centers throughout the afternoon, instead of the information automatically being entered into the computer. The FAA reports it's now back to normal.
There were delays of about 30 minutes at SFO right after the outage happened.
