The Federal Aviation Administration says flights from airports in the Los Angeles area were grounded for more than an hour due to a computer failure at an air traffic control facility in the region.
Outbound flights at Lindbergh Field were briefly delayed, airport operations said, but were now back on schedule.
Dozens of planes heading into the Los Angeles area were diverted elsewhere Wednesday afternoon or prevented from taking off at airports including Phoenix, Las Vegas and Oklahoma City.
The "ground stop" in Southern California affected several airports including Los Angeles International, the nation's third busiest. An airport spokeswoman said more than 30 departing flights were held on the ground.
A notice posted on the FAA website said planes were not allowed to depart Los Angeles because of a failure of the agency's En Route Automation Modernization system.
The computer system allows air traffic controllers at several dozen "en route centers" around the country to identify and direct planes at high altitudes.
