LONDON Thousands of travellers were delayed at major airports across England on Saturday because of a technical problem at an air traffic control centre.
Disruption was reported at most airports including Heathrow, Gatwick and Stansted, after what National Air Traffic Services (NATS) said was a computer glitch at its control centre in Swanwick in Hampshire.
Passengers were being hit by average delays of between one and two hours but the knock-on effects were expected to last through Saturday afternoon.
NATS said the problem began when its night operating system failed properly to switch over to daytime mode.
"At night, when it's quiet, we can combine sectors of airspace. When it gets busy in the daytime we split the sectors out again," it said in a statement.
"We experienced a technical problem in the early hours of this morning, which means that it hasn't been possible to ... split out the sectors for the busier daytime traffic."
NATS did not give any estimate of when normal service would be resumed.
"Engineers are working to rectify the problem as soon as possible," it added.
Heathrow, Britain's busiest airport, had cancelled 60 flights by 0945 GMT, a spokesman said.
Edinburgh, Manchester, Birmingham, Southampton, Luton, London City, Newcastle, Exeter and Bournemouth Stansted also reported delays and were asking passengers to check with their airlines.
Flights from Scotland were less affected.