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Fail-Safe Fails: FAA Looks for Answers

The agency suspects design flaws caused the blackout at a Palmdale center, halting flights.

July 20, 2006|Jennifer Oldham and Ricardo Alonso-Zaldivar | Times Staff Writers

When radar screens suddenly went dark at Palmdale's regional air traffic center on Tuesday, controller Bruce Bates and his colleagues knew instinctively what to do: They grabbed their cellphones and started calling for help.

The simple solution to a high-tech problem played out as pilots flying at high altitudes over Southern California and much of Nevada and Arizona tried in vain to reach controllers in the Los Angeles Air Route Traffic Control Center, where even the radios were dead.

The trouble had begun an hour before, when a traffic accident downed power lines to the facility, triggering backup generators.

But those units were soon also knocked out, federal officials said Wednesday, by a system of surge protectors designed to avoid just such a crisis.

"The anxiety level definitely shot through the roof," Bates said, describing the scene. "We have seen glitches like a pop in the system, but the system keeps functioning. When it didn't come back on after about 10 to 15 seconds, all of us knew there was a major problem."

The phone calls for help went to controllers at other centers across the West, and they ultimately guided pilots to their destinations.

Federal officials said there were no close calls between aircraft as a result of the two-hour power outage at the Palmdale facility Tuesday evening. But controllers said it could take weeks to analyze radar data to ensure that safety wasn't compromised by planes flying too close to one another.

The center, which directs commercial jets flying at high altitudes, initially lost power after a truck hit a nearby utility pole around 4:19 p.m. Backup generators kicked on immediately. But about 75 minutes later, a system designed to protect sensitive equipment failed, causing radar to go dark.

The outage snarled air traffic across the country, causing hundreds of flights to be held on the ground in other cities while controllers in Oakland, Salt Lake City and Albuquerque diverted flights already in the air away from the Los Angeles Basin.

On Wednesday, local officials demanded to know why backup systems weren't more robust. An aide to Los Angeles County Supervisor Mike Antonovich, who represents Palmdale, said the supervisor asked Southern California Edison to provide a dedicated power line to the regional facility to prevent similar incidents.

"We want to ensure that a traffic accident in the Antelope Valley can't knock out air traffic control for the entire western United States," said Antonovich spokesman Tony Bell.

Controllers lost radio and radar communication with pilots after the failure of several switches that are intended to keep power spikes from damaging air traffic control systems. Technicians attributed the problem to an order from the Federal Aviation Administration two years ago that the system be reduced to save money.

"They did that in order to save money on the electrical bill," said Ray Baggett, Western region vice president for Professional Airways Systems Specialists, the union that represents FAA technicians. "They are doing everything they can to reduce redundancy and back up systems. They are decreasing their safety margin ... to achieve cost efficiency."

FAA officials denied that cost-cutting played any role in the failure, saying that their initial conclusions are that the system went down because of the way it was designed.

"We are absolutely not reducing redundancies to improve efficiency, that's not a policy," said Laura Brown, an FAA spokeswoman.

Fifteen minutes after the backup generators went down, the radio systems at the Palmdale center came back on, allowing controllers to talk with pilots, but the radarscopes remained down until about 7:30 p.m.

This was the second time in less than two years that troubles at the Palmdale center, which directs high-altitude traffic over an area of about 178,000 square miles, disrupted air service nationwide.

In September 2004, the facility lost radio communications for nearly three hours after a technician failed to perform required maintenance. Backup generators had also been configured incorrectly, which caused them to fail.

The shutdown led to at least five instances in which planes flew too close to one another.

Tuesday's breakdown may have implications for air traffic control systems throughout the country, because the backup power system that failed is also used in other control centers that handle both high-altitude flights and planes that are approaching and leaving major airports.

"We are going to have to do some research on the failure and how to prevent it" in other control centers," said Richard Riggs, a systems expert with the FAA technicians' union.

The system that failed, known by the acronym ACEPS, was installed by the FAA during the 1990s as part of a major modernization effort designed to make the air traffic control system more reliable.

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