FAA still seeking cause of flight plan system shutdown

Computerworld - Investigators still don't know what caused a computer system problem on Friday that shut down one of two systems used by the Federal Aviation Administration to distribute aircraft flight plans filed by pilots across the U.S.

Paul Takemoto, a spokesman for the FAA in Washington, said today that FAA technicians have been on the ground in Atlanta since the National Airspace Data Interchange Network (NADIN) unit shut down at 6:57 a.m., causing flight delays and cancellations that were exacerbated by strong thunderstorms on the East Coast. A second NADIN system, located in Salt Lake City, continued to operate when the Atlanta unit failed, but it was overwhelmed when systems operators switched the Atlanta workload over to process all flight plans for the entire country, he said.

The cause of the shutdown is still not known, Takemoto said. "They're still running tests to find the problem. They've been in Atlanta since Friday and they're going through everything to find the cause."

There have been no further problems with Atlanta's NADIN system since it was returned to service just before noon on Friday. It took almost another hour to get NADIN operating for the New York flight control area, but service was restored there at 12:48 p.m. that same day.

Residual delays and flight cancellations continued into the evening, but many of those flight problems and some 800 canceled flights were the result of severe thunderstorms that rocked much of the East Coast, he said.

NADIN is used to distribute flight plans filed by pilots before their planes depart, allowing air traffic controllers along the routes to know when planes are departing, where they are headed, the type of aircraft being flown, as well as other detailed information used to track and guide flights across U.S. airspace. The information appears on flight controllers' screens so flights can be identified.

Data for any plane large or small, private or commercial, that files a flight plan is entered into the NADIN system, Takemoto said.

NADIN was developed in the early 1980s by a Dutch company, but is slated for replacement by October 2008 with a system being built in-house by the FAA, he said.

"There wasn't any impact on safety," Takemoto said, since the flight plan information was entered manually when the NADIN system was out of commission. The manual entry of the data was the cause of much of the delays, he said.

Tim Wagner, a spokesman for Forth Worth, Texas-based-American Airlines Inc., said his airline had about 88 flight cancellations on Friday because of the NADIN problems and bad weather. Passengers also experienced flight delays of one hour to 90 minutes, he said.