Los Angeles air-traffic controllers grounded hundreds of airliners headed into the Southwest on Thursday because of repeated failures of the radar computer guiding flights into the region. “We’re in a national ground stop now. All aircraft coming into this area will be stopped on the ground,” Federal Aviation Administration spokesman Jerry Snyder said after the computer failed for a second time. A backup system took over and there were no safety problems for aircraft in the air, Snyder said. The failure was the result of a computer software upgrade Wednesday night. “When the systems were being brought back up on-line, it failed. It’s not accepting the software,” Snyder said. The backup system doesn’t have the automatic feature that passes off planes from one regional controller to another, and requires a controller to manually type the flight information.
