§ Mr. Carmichael
To ask the Secretary of State for Transport (1) on how many occasions the National Air Traffic Control Service's computer has malfunctioned; 
(2) what recent delays have been caused by the failures of the National Air-Traffic Control Service's central computer; 
(3) what steps are being taken to improve performance of the National Air Traffic Control Service's central computer; 
(4) what has been the average duration of blackout during failures of the National Air Traffic Control Service's central computer. 
§ Mr. Spellar
While these are essentially operating matters for NATS my understanding is as follows.
NATS computer systems have failed on three occasions in recent months—at West Drayton on 27 March with aggregate total delays to all affected aircraft of 88,000 minutes; West Drayton again on 10 April with delays of 34,000 minutes; and at Swanwick on 17 May with delays of 82,000 minutes. NATS first action is to take immediate steps to reduce traffic volumes to levels that can be safely handled by the contingency arrangements in place. While this impacts on airline punctuality, the first priority must be to ensure safe operation.
There was no interruption to radar services, and at no time did controllers lose contact with pilots. Actions in regard to software and equipment have been taken to prevent any recurrence of these problems.