March 17, 2000

Airport radar system to get 'thorough stress test' The air traffic control system failed last week. It will be shut down and tested after 1 a.m. Sunday and Monday, the FAA said.

By Henry J. Holcomb

INQUIRER STAFF WRITER After a two-day review of recent Philadelphia air traffic control radar failures, investigators yesterday ordered a "thorough stress test" of the system this weekend.

No flights will be disrupted and safety will not be compromised, said Alan Moore, the Federal Aviation Administration's acting airways facilities director.

The FAA also said yesterday, for the first time, that it would be late 2002 or 2003 before the 40-year-old air traffic control system in Philadelphia would be replaced.

The most recent of four failures in less than a year at Philadelphia International Airport occurred at 8 p.m. last Friday. There were three computer failures, which FAA technicians called "scatters," between 8 and 8:19 p.m.

In each instance, controllers could still see blips on their screens, representing aircraft. But they lost critical data that gave each blip's flight number, speed, altitude, and direction of travel.

This weekend's tests on the problem-plagued system will be done after 1 a.m. Sunday and Monday. Traffic is so light at these hours that the Philadelphia International Airport system can be shut down and control shifted to the Willow Grove Naval Air Station.

This is the first opportunity to conduct the unusual stress tests since the FAA assembled its five-person team on Monday at the behest of U.S. Sen. Arlen Specter (R., Pa.). Local air traffic controllers have been urging the tests since last spring and were on hand yesterday to remind reporters.

On other nights each week, the busy United Parcel Service hub and other cargo flights keep the Philadelphia airport busy all night.

Specter turned up the heat on the FAA yesterday, summoning its investigators to a news briefing in the lobby of the Wyndham Franklin Plaza Hotel, where the Pennsylvania AFL-CIO was holding its annual convention.

The problems occurred in the computer system at the Philadelphia airport control tower that controls flights arriving and departing from the region's 25 airports, including Trenton and Wilmington.

When the crisis began, investigators said yesterday, controllers immediately reduced the number of planes over the Philadelphia area - mainly by holding 36 departing flights on the ground. The FAA said four flights were put in holding patterns in the air.

The air traffic control centers in New York and Washington, which control inter-city traffic, were told not to hand off any more flights to the Philadelphia terminal area.

The FAA's Moore emphasized yesterday that no lives had been endangered. Still, he said, the malfunction is "a great concern to us. We've assembled a team of experts who are now here. They are evaluating the whole system. They are looking at the hardware, top to bottom. They are looking at the software code to see if it's doing exactly what we want."

The team has already replaced nine of the 500 computer circuit boards in the system, said Steve Gallegos, the FAA's deputy operations director in Washington and chief of the investigating team.

The five-person team has called in three top specialists to aid in the search for what caused the circuit boards to fail.

The tests this weekend will replicate various worst-case scenarios to put both the hardware and software under stress and expose any other damage that could lead to future failures, Gallegos said.

The FAA officials said that in each failure last Friday, the system was disrupted for only 16.5 seconds, and that proper separation between aircraft was maintained.

Daniel Mullin, president of the Philadelphia local of the Air Traffic Controllers Association, an AFL-CIO union, listened to the briefing yesterday and said his members were angry that the review now under way was not done when the problems first surfaced last spring.

A 16.5-second failure is not significant, he said, "when everybody does the turns you tell them to and stops at the altitude you told them to."

But there are times, he said, "when four things go wrong at once - you tell a guy to turn right and he turns left, and you see a guy you told to climb to 10,000 feet passing 10 and going to 11,000."

Planes on a collision course can be flying at 600 miles an hour, Mullin said. "That's 10 miles a minute . . . 161/2 seconds can seem like an eternity.

"http://www.phillynews.com/inquirer/2000/Mar/17/city/AIRPORT17.htm

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-- Martin Thompson (mthom1927@aol.com), March 17, 2000