AIR TRAVEL NIGHTMARE RADIO GLITCH STRANDS THOUSANDS IN SOUTHLAND.

Byline: Lisa Mascaro and Jennifer Radcliffe Staff Writers

A radio communication failure Tuesday at the regional air traffic control center in Palmdale grounded airliners in Southern California and disrupted travel across the United States, stranding tens of thousands of travelers and forcing hundreds of planes to be rerouted.

The massive breakdown in the air traffic system occurred at 4:40 p.m. when the Los Angeles Air Route Traffic Control Center in Palmdale, one of 20 centers across the country, lost its primary communications system, cutting off radio contact with about 800 planes in flight. By the time radio communications were restored about 8 p.m., the disruption had caused havoc across much of the country.

Los Angeles International, Burbank, Ontario and airports in Orange County, San Diego and Las Vegas took the brunt of the failure. Flights into the region were held on the ground and those already in flight were being diverted elsewhere, while outbound planes were prohibited from taking off well into the night, authorities said.

By 8 p.m., the Federal Aviation Administration ban was lifted, but the system was only operating at half capacity and wasn't expected to get back to full operations until 3 a.m.

``I don't think in this case safety was ever compromised at all,'' said FAA spokeswoman Laura Brown. ``We safely landed all those planes.''

Frustrated passengers at Burbank's Bob Hope Airport stood in long lines trying to make new arrangements.

``I can't get home,'' said Julie Brekke, who was trying to return to Phoenix after a day of business meetings in Los Angeles. ``They can't even guarantee I'll be flying out tomorrow.''

Darren Conzo of San Dimas and his wife were expected at an Internal Revenue Service conference in Las Vegas today.

``We're not happy,'' Conzo said Tuesday night. ``We have a rental car just in case. We're weighing our options now.''

LAX regularly handles 3,600 flights a day, and reported 400 flights were expected to have been canceled, diverted or delayed.

A spokeswoman for Southwest Airlines, which operates busy terminals at four Southern California airports, said at least 25 inbound flights had been diverted elsewhere. She couldn't say how many outbound flights were canceled.

``It is quite an inconvenience to all of our customers coming in and out of Southern California,'' said Southwest spokeswoman Whitney Eichinger. ``We're doing the best we can.''

The shutdown started at 4:40 p.m. when the Federal Aviation Administration reported a failure in the radio system that provides air traffic control for planes coming in and out of the region.

The problem hit all major Southern California airports serviced by the FAA's Los Angeles Air Route Traffic Control Center in Palmdale, which covers a 200-mile radius and includes airports in Los Angeles, Burbank, Ontario, Orange County, San Diego and Las Vegas.

More than 800 flights were headed to Southern California at the time, and many were initially allowed to land as the FAA relied on other regional centers, including one in Albuquerque, to guide planes.

But eventually all flights into the region were being diverted and new flights into Southern California were grounded.

``Any plane destined for L.A. from someplace else, you're not going to be able to leave the ground,'' said FAA spokeswoman Brown.

The FAA could not readily identify the problem.

The center in Palmdale is supposed to provide radio communication to the planes as they enter or leave the region, before and after they talk with the airport towers.

``We know that the radio system didn't work, and the back-up system didn't work,'' said the FAA's Brown. ``And that's unusual, because most of our systems have back-up systems that kick into place usually.''

The Palmdale center has had problems in the past. In October 2000, new radar software failed, causing a similar shutdown of air travel that stranded passengers for hours. Another glitch caused the radio system to go out in 1997, though no flights were delayed at that time.

Brown said there was no safety threat in Tuesday's outage. Still, travelers felt the brunt of the problem.

At LAX, the Backlot Deli and Bar's Viviana Gomez reported a steady flow of customers as flights were halted.

Ontario Airport reported dozens of delayed flights.

In Burbank, stranded passengers gathered at the airport bar, read magazines and lounged using their bags as pillows.

One man played a game of solitaire on his laptop computer while others simply gave up.

Spokesman Victor Gill said by early evening traffic was backing up at the Burbank airport.

``It's kind of like commuter hours, you do it in the morning, then in the evening,'' he said. ``It'll upset things. It'll upset the flow of traffic.''

One frustrated passenger said when the flights stopped, waiting travelers were unnerved.

``The terminal kind of panicked a little. Nobody knew what's going on,'' said Clyde Fuchino of Sacramento. ``We still don't know what's going on.''

Lisa Mascaro, [phone]

lisa.mascaro(at)dailynews.com