More problems 'inevitable'

Further problems with air traffic control systems are "inevitable", experts warned today.

Philip Butterworth-Hayes, a civil aviation editor at Jane's Information Group, blamed the lack of a single system for all of Britain. "The problem is there are so many different systems trying to work together," he said.

Tony Collins, executive director of Computer Weekly, described the system at West Drayton, which creates flight progress plans for controllers in Swanwick and Manchester, as a "patch-up".

He added: "Although the hardware is new, the software is old. They have been upgrading software but it's like adding new bits to an old car. There is also the question of why they were testing on an operational system rather than on a simulated one."