CHAOS that hit UK airports yesterday began to clear last night, with air traffic control company Nats declaring its systems are back to full operational capacity.
But flight mayhem at some of the busiest routes could stretch into the weekend.
Dozens of flights were cancelled and many others delayed after a computer failure at Nats company headquarters yesterday afternoon.
"Following a technical fault with the flight data system used by air traffic controllers at Swanwick, Nats can confirm that the system has been restored to full operational capability and a thorough investigation is continuing to identify the root cause," a spokesman said at about 8pm.
"Although operational restrictions applied during the failure have been lifted, it will take time for flight operations across the UK to fully recover so passengers should contact their airline for the status of their flight. We apologise for the impact that this issue has had and the delays and inconvenience caused."
The company ruled out a power cut as the source of the glitch at the £700 million centre at Swanwick, Hampshire.
Airports as far north as Aberdeen and Edinburgh were affected by the computer problem. Other airports that reported delays this afternoon included Manchester, Stansted and Luton.
Budget flier easyJet said: "EasyJet has had to cancel ten flights to and from London Gatwick. However, all aircraft which were earlier diverted have all now continued to their original destinations. In addition, it is likely that other flights to and from the south of the UK will suffer delays this evening."
The airline said it had cancelled two Gatwick-bound flights scheduled for today.
Gatwick Airport said yesterday evening: "Some cancellations should be expected and passengers are advised to contact their airline for the latest flight information.
"All departing flights were affected for a period but the situation is improving and we (are) hoping to restore a near normal service later this evening."
* DELAYED: People wait at Terminal 5 of Heathrow Airport last night
PICTURE: Steve Parsons/PA