Near miss at LAX blamed on radar

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Wednesday, April 03, 2002

Near miss at LAX blamed on radar

By Ian Gregor

DAILY BREEZE

A computer system designed to help prevent runway collisions was not working at Los Angeles International Airport when an arriving jet blundered onto a runway where another passenger plane was taking off a week ago, air traffic officials say.

The departing plane, a Chicago-bound United Airlines Boeing 757, took off before it reached the spot where a Delta Airlines 737 had stopped.

It's unclear whether the Airport Movement Area Safety System, or AMASS, would have helped air traffic controllers respond to this incident, sources said. AMASS analyzes information from ground radar and sounds an alarm when it detects vehicles or planes that might be in danger of crashing on the airfield.

But the episode points up a bigger problem with the air traffic control system that serves the world's third-busiest airport: AMASS wasn't working because the ground radar on LAX's south side was broken — a snafu that air traffic controllers say occurs all too frequently.

Ground radar is critical equipment that controllers use to locate planes at night and during bad weather. The system remained out of commission at LAX for a week because the Federal Aviation Administration was unable to find a replacement for a broken part on the radar transmitter.

“I just cannot believe the FAA can't figure out a way to make it work faster,” grumbled one veteran LAX air traffic controller, who asked not to be identified.

“Can you imagine if someone said it would take (that long) to get a company's computer server back up? We're talking about something here that's saving people's lives.

“From the time it went out, it should have been back on line in 48 hours — and that's being generous.”

Several knowledgeable sources say the March 22 incident began about 4 p.m. when Delta Flight 1564 from Salt Lake City landed on the outer runway on the airport's south side. An air traffic controller instructed the pilot to turn off the runway onto a taxiway near the center of the airfield and stop before reaching the inner runway. The pilot confirmed the instruction. The controller then cleared United Flight 118 for takeoff on the inner runway.

But the Delta pilot failed to stop where he should have and nosed about 15 feet onto the inner runway. By this time, United was too far down the runway to safely abort its takeoff.

Because a Boeing 757 requires relatively little runway length for takeoff and because a strong head wind provided lots of lift under its wings, the United jet was able to leap into the air well before it reached the Delta 737. But the situation would have been dire if the departing plane have been a jet that required longer takeoff rolls, such as a big 747 or 767, or even a smaller MD-80, controllers said.

A 747's 100-foot-long wing would have cut through the Delta jet's cockpit and several rows of seats.

“If it was a loaded 747 heading to Tahiti, it would have been a bad situation,” said Mike Foote, the LAX air traffic controllers union representative. “We're fortunate it was the aircraft it was.”

The incident was the first “runway incursion” of 2002. LAX logged eight runway incursions in 2001 and 2000, 12 in 1999 and 13 in 1998, FAA statistics show.

The incident occurred less than three weeks after FAA Administrator Jane Garvey held a news conference at LAX to tout the benefits of AMASS, which has been credited with alerting controllers to looming airfield crashes in San Francisco and Boston.

AMASS might or might not have helped at LAX on March 22. If the departing jet had been heavier, a working system might well have saved hundreds of lives, controllers said.

But the system never had a chance to issue an alarm because the south side ASDE-3 ground radar to which it is linked was out of commission, Foote said.

The ASDE-3 is so accurate that it shows controllers the image of an engine on a jumbo jet that's taxiing 275 feet below on the airfield. It is especially valuable in foggy conditions and at night.

Without the radar, controllers depend on flight crews to report their positions during these conditions. This means more communication between cockpits and controllers and more chances for confusion, Foote said. And pilots often don't know if the tails of their planes are clear of runways because jets don't have rear-view mirrors.

The controllers union filed a formal complaint with the FAA over the radar failure, Foote said.

“I think it would be difficult for people to understand how an accident occurred at L.A. when ASDE and AMASS were not working,” Foote said.

Airfield crashes that killed scores of people in Taipei and Italy in recent years occurred partly because the airports did not have ground radar or because the systems were not working.

LAX's south side ground radar came back into service Thursday after being down for a week because of a broken “flexible wave guide,” FAA spokesman Jerry Snyder said. The 6-inch, pipe-shaped part guides radar signals from a transmitter near Imperial Highway to its antenna, which relays the signals to equipment in the control tower, he said.

The FAA found a replacement wave guide at the agency's William J. Hughes Technical Center at Atlantic City International Airport and the part was shipped to LAX on Wednesday, Snyder said. He said he did not know why the agency was unable to find a replacement part more quickly.

Previously, the ground radar was down because of intermittent problems with a modulator, Snyder said.

“It goes out more than you would think; it's not unusual for it to happen a few days here and there,” Foote said. “As a controller, you get used to working with a piece of equipment, and when it's taken from you, it's more traumatic than if you never had it in the first place.”

http://www.dailybreeze.com/content/bln/nmnearmiss30.html

-- Anonymous, April 03, 2002


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