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Human Errors Silenced Airports

A controllers union official describes 'harrowing' incidents in the sky, but the FAA insists the radio system failure posed no threat.

September 16, 2004|Ricardo Alonso-Zaldivar, Eric Malnic and Jennifer Oldham | Times Staff Writers

Two separate human errors caused a breakdown in radio communications that brought Southern California's major airports to a near-stop Tuesday and led to at least five instances in which planes came too close, Federal Aviation Administration officials said.

"A loss of communication is a serious matter, and it should not have occurred," Rick Day, a senior FAA official, said Wednesday.

On Tuesday, FAA officials had insisted that the more than three-hour system shutdown posed no safety risks. But they acknowledged Wednesday that they were investigating five incidents in which planes lost the required separation distance during the first 15 minutes of the communications breakdown.

In two cases, large airliners -- a UPS cargo plane and a Northwest Airlines flight bound for Southern California airports -- came much closer to small corporate jets than federal guidelines allow, requiring at least one pilot to take corrective action. FAA officials repeated Wednesday that they did not believe lives were ever at risk.

The agency's radio system in Palmdale shut itself down Tuesday afternoon because a technician failed to reset an internal clock -- a routine maintenance procedure required every 30 days by the FAA. Then a backup system failed, also as a result of technician error, officials said.

The radar system in Palmdale, contrary to what some FAA and union officials had said Tuesday, did not shut down.

The radio system that crashed about 4:30 p.m. Tuesday at the Los Angeles Air Route Traffic Control Center in Palmdale is a high-tech touch-screen tool that allows air traffic controllers to quickly communicate with planes in transit. Controllers at the Palmdale facility communicate with cruise-altitude air traffic across Southern California and most of Arizona and Nevada, an area of about 178,000 square miles.

FAA officials said they had known for more than a year that a software glitch could shut down radio communications and were in the process of fixing it. In the meantime, they required manual resetting of the communications system -- a process they described as similar to rebooting a personal computer.

The problem so far has been corrected only in Seattle, one of 21 FAA regional air-traffic control centers that have used the system since the mid-1990s.

The radio failure rippled throughout the nation's airports, grounding hundreds of commercial flights and forcing controllers working from other centers to divert hundreds more to locations outside Southern California.

Los Angeles International Airport officials said about 30,000 passengers were affected, with 500 or 600 spending the night in the terminals. The backlog of incoming flights was not cleared until 3 a.m. Wednesday. At LAX, 450 flights were diverted or canceled and another 150 were delayed. An additional 32 were canceled Wednesday morning because the aircraft did not arrive Tuesday night.

Other airports -- Ontario, Bob Hope, John Wayne, Long Beach and Palm Springs, as well as San Diego -- experienced significant delays, and airports throughout the West took diverted flights.

The computer glitch that snarled air traffic was first discovered more than a year ago in Atlanta after the FAA upgraded its computers.

"That's why we built in strict maintenance procedures and protocols," said FAA spokesman Greg Martin. He said his agency is aggressively pursuing the reason why the routine and simple procedure was skipped at the Palmdale air traffic center.

Tuesday's communications failure marks the first time that the backup system has failed when the radio system shut down, Martin said.

The backup's failure left controllers with no way to communicate with other FAA centers or the high-altitude flights displayed on their radar screens.

Hamid Ghaffari, a union official at the Palmdale facility, described a scene of high tension Tuesday evening as controllers tried to use personal cellphones to warn controllers at other facilities and watched close calls unfold without being able to alert the pilots.

Martin called the remarks "wildly overstated" and said "none of these incidents under our definition would be considered near midair collisions."

Ghaffari said three controllers had filed job injury claims as a result of the stress, but said none of them would speak to the media.

"You can see planes getting close together, but you can't talk to them," said Ghaffari, describing conditions Tuesday evening.

"That's what made it particularly harrowing."

Once the Palmdale radio system failed, controllers at other FAA facilities, following contingency plans, took over communication with scores of airborne flights.

"En route aircraft were safely handed off to other air traffic control facilities, as designed," Martin said.

Controllers said they believed at least two of the incidents were dangerous, and FAA officials acknowledged those two were the most serious.

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