Airport bosses said the majority of journeys to destinations in England were affected by yesterday’s disruption, with lengthy queues forming at ticket desks.
Officials at London Heathrow said the problem had been caused by a power outage at the National Air Traffic Services (NATS) control centre in Swanwick, prompting the cancellation of 50 flights.
They said there would be no departures or arrivals at the west London airport and initial reports suggested all airspace was closed until around 7pm last night.
The bug was fixed just after 4pm and NATS chiefs confirmed they were returning to “normal operations”.
Five flights from Edinburgh were cancelled, with scores of passengers left stranded.
Some complained that airport staff had failed to inform them of the status of their flight or what had caused the problem.
Gareth McPherson, 29, from Cambridge, who was due to fly to the Capital from London Stansted, told how he was facing delays of more than an hour. I’ve got no idea what time I’ll get to Edinburgh, which isn’t a great start to the weekend,” he said. It’s really gutting.”
Posting on Twitter, Fiona Whitworth said: “Living the ATC [air traffic control] chaos at Edinburgh Airport. It’s annoying & unsettling but can’t do anything about it so chilling out.”
And another passenger said: “Desperate scenes at Edinburgh Airport as staff remain calm and passengers complain.”
Bosses at Edinburgh Airport said they were keeping a close eye on the situation and urged passengers to obtain updates from ticket providers before travelling.
A spokesman said: “Due to the earlier computer failure affecting London airspace we are experiencing some delays on flights which are due to travel south. We are monitoring the situation closely and are doing all we can to minimise disruption for our passengers. We encourage passengers to contact their airline if intending to travel this evening.”
Yesterday’s problems were condemned as unacceptable by UK political leaders.
Transport Secretary Patrick McLoughlin said: “Any disruption to our aviation system is a matter of the utmost concern, especially at this time of year in the run-up to the holiday season. Disruption on this scale is simply unacceptable and I have asked NATS for a full explanation of this incident. I also want to know what steps will be taken to prevent this happening again.”
The state-of-the-art centre at Swanwick – which cost £700 million to build – has been subject to a number of computer break-downs since NATS moved there from its old headquarters in West Drayton in 2002.
One of the worst problems occurred on December 7 last year, when thousands of passengers were left stranded after flights were grounded following a technical fault.