Software glitch delays London flights

LONDON -- Flights are back to normal today after some U.K. air-traffic control computers went down Saturday for the second time in eight days, causing delays at the three British Airport Authority (BAA) airports in the southeast, including Heathrow Airport, one of the world's busiest international airports.

The National Air Traffic Services (NATS) flight data processing system failed for three hours Saturday, according to Richard Wright, a spokesman for NATS.

"This was not a safety issue," he said. "It didn't affect the radar screens, they did not go blank."

At Heathrow alone there were 310 flight cancellations Saturday and 133 Sunday, according to a BAA spokeswoman.

Computer glitches were still occuring at Heathrow Monday. In the departure hall at Terminal 1, screens displayed at least one British Airways flight, BA778 to Stockholm, as cancelled, although it was operating normally. Boarding passes for the flight didn't state a departure gate number, however, which irritated some passengers lining up at British Airway's customer service desk to inquire about the status of the flight.

On Sunday, passenger lines to the security check at one point lined the departure hall in Terminal 2.

Saturday's failure was caused by a software malfunction, but the error earlier in the month, which caused the system to shut down for 20 minutes, was caused by incorrect input by an adjoining air-traffic control center.

"Saturday was caused by a software problem, not a human error," Wright said. "This is the first serious problem we've had in 15 years," he added.

The software, based on IBM Corp.'s Federal Systems Software, was developed by NATS, Wright said.

"There is similar (software) in place throughout the U.S. and in a few other countries as well," Wright said.

The system automatically produces flight plans, or "strips," which are used as a route plan by aircraft while in U.K. airspace. "A data problem caused the system to shut down, so the plans had to be manually produced," Wright said. This led to delays, because the routes couldn't be produced as fast manually as by computer, so NATS was forced to reduce the number of flights entering and leaving U.K. airspace.

"Normally, at Heathrow, you'd probably have about 45 takeoffs in an hour. While the system was down, we could only allow half of those," Wright said. "And you can't stop an airplane that's on its way so you have to call Paris and Rome, telling them to limit their number of flights to Heathrow as well," he added.

When air-traffic computers in Swanwick, Hampshire, take over the current systems in 2001 or 2002, they will continue to use the current data processing system, Wright said.

"It will still be in use until its planned replacement in 2007," Wright said.

Terho Uimonen contributed to this story.

Related stories:

Copyright © 2000 IDG Communications, Inc.

7 inconvenient truths about the hybrid work trend
Shop Tech Products at Amazon