But flight mayhem at some of the nation’s busiest thoroughfares could stretch in to the weekend.
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 tomorrow.
Gatwick Airport said on Friday 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.”
At Heathrow, a spokesman said there had been 70 cancellations out of about 1,300 scheduled flights.
“They’re coming back to normal now,” he said.
18.20: NATS managing director of operations Martin Rolfe defended his organisation’s handling of the chaos.
“It was a technical failure at our Swanwick centre which handles 6,500 flights a day,” he said.
“We went through our backup systems and restored things relatively quickly but not without delays to passengers, which we hugely regret.
“These things are relatively rare. We are a very busy island for air traffic control, so we’re always going to be operating near capacity.
“What we’ve seen today is a very quick response. We didn’t close any airports, we didn’t close any airspace. We reduced the flow to make sure everything could be handled safely.”
18.15: NATS has ruled out a power failure as the cause of the airport crisis.
A software problem is now thought to be the likely cause.
In a statement the service said: “We are investigating the cause of this fault but can confirm that it was not due to a power outage.”
Earlier reports had suggested a power failure at Swanwick air traffic control centre was behind the closure of London airspace.
It is now being described as a “technical problem”.
Airports as far north as Aberdeen and Edinburgh has been affected by the shutdown. Other airports that reported delays included Birmingham, Manchester, Luton and Bristol.
There were also hold-ups at Stansted and Gatwick but these two major south east England airports appeared to have escaped more lightly than Heathrow where the rate of 80 to 90 flights handled every hour means even a comparatively short systems failure leads to severe disruption.
18.06: Luton flights disrupted. Normal service unlikely to return to UK airports until Saturday.
17.51: Which? reminds passengers to claim for any losses.
Which? executive director, Richard Lloyd, said: “The Denied Boarding Regulations provide a means for consumers to claim compensation for delays and cancellations however if an airline is able to demonstrate the cancellation or delay was due to extraordinary circumstances then they don’t have to pay out.
“Passengers may however still be entitled to refreshments, free phone calls and overnight accommodation depending on how long the delay is, how far you are flying and whether the flight is to or from an EU or non-EU airport or on an EU or non-EU carrier.”
Further advice on flight delays and cancellations is available on the Which? Consumer Rights website (www.which.co.uk/consumer-rights).
17.42: Disruption “simply unnacceptable”
Transport Secretary Patrick McLoughlin has slammed NATS for tonight’s power failure.
He said: “Disruption on this scale is simply unacceptable and I have asked Nats for a full explanation of this evening’s incident.”
17.40: NATS has some previous with computer glitches. There were similar problems twice last year in July and December last year.
17.37: The upside of airport chaos – amazing views.
17.26: 50 flights cancelled at Heathrow and more expected.
Heathrow has had to cancel 50 flights as a result of the earlier glitch which lasted barely half an hour from about 3.30pm until 4pm.
Airlines flying from Gatwick Airport, just south of London, were still deciding at about 5.15pm whether any cancellations would be needed to clear the backlog.
No flights had yet been cancelled altogether, a spokesman said, although some have experienced delays of about 45 minutes.
The airport was not able to confirm how many flights had been affected.
17.23: Long haul flights from Heathrow are being prioritised, followed by European flights and finally UK flights.
17.19: Businesswoman Katharine Tulley from Manchester stranded at Heathrow says they have been told their flight to Manchester is delayed by six hours. She and her colleagues are now getting a taxi from Heathrow to Manchester.
“The last time I came to Heathrow this happened. I think I must be cursed. But I am being philosophical. There are people trying to travel to the other side of the world in a worse position than me.”
17.17 Although the problem now appears to have been fixed, it’s likely to have a knock-on effect for passengers travelling into London from around the world.
Matt Navarra says on Twitter his flight from New York to London has been delayed by several hours.
17.12:Trickle of planes now leaving Heathrow
17.03: Stansted says flights are taking off but there are holdups
16.57: British Airways warns that it will take some time for flights to return to normal.
16.55 NATS says flights are departing but there will be delays.
16.50: Our reporter at Heathrow Terminal 5 says passengers are now being allowed to board planes
16:40: Gatwick tells passengers to travel to the airport as normal but to contact tour operators for updates.
16:39: Heathrow says flights have started to depart.
16:35: Some trapped passengers getting into the Christmas spirit and not letting the travel misery ruin their holidays.
16:29: Computer expert Professor Ian Allison, Head of the School of Computing Science and Digital Media at Robert Gordon University (RGU), says it must have been a “major failure” to cause the system to crash.
“This failure is most surprising as these systems have high levels of resilience built into them,” he said.
“Software is written to a high level of engineering to ensure the safety of passengers. On this occasion it seems to be a server failure – i.e. an infrastructure failure on which the software is running. I am sure the systems will have been designed to cope with this type of failure – normally to “fail over” safely to another mirror server. So it seems to be a major incident that has caused the contingency plans to fail as well as the primary system. It is difficult to assess the cause or how long it will be before the system is returned to normal without knowing more but I am sure that they will be looking to restore the system using a back-up data centre.”
16:26: Delays expected to continue as NATS attempts to get flights moving.
16:25: NATS say the problem has been fixed.
16:24: Some passengers trapped on planes report they have not been given updates for when the problem will be resolved.
16:22: Airports across the country have been affected. Passengers reporting delays in Aberdeen, Bristol, Exeter and Southampton.
16:11: Gatwick Airport reports that some of its planes are starting to depart.
16:10: Some passengers are stuck on planes.
16:09: Problems expected until 7pm on Friday.
16:08: Gatwick Airport says flights are still landing but none are departing.
16:06: Heathrow Airport warns passengers to expect delays.
A spokesman for Heathrow said: “There is a technical problem at the NATS control centre in Swanwick, which is affecting UK airspace. Flights are currently experiencing delays and we will update passengers as soon as we have more information.”
16:04: NATS, the national air traffic control body, says it working to resolve the problem.
“Every possible action is being taken to assist in resolving the situation and to confirm the details,” said a spokesman.
“Further information will be released as it becomes available.”
16:00: All flights that pass through London airspace have been grounded.
15:58: Flightradar24 reporting only a few landing craft now left in London airspace.
15:56: There are no flights departing from London airports at the moment.
15:54: Are you stuck on the runway? Send us your images to email@example.com
Flights being rerouted
15:49: Major airports across the UK affected.
15:47: Passengers are stuck on planes which have been grounded.
15:36: All flights have been grounded across the UK due to air traffic control computer failures
A failure of the Flight Data Computer Server at London ACC meant no traffic could be accepted into London airspace until 7pm, the European flight safety body says.
NATS, the national air traffic control body, said: “NATS can confirm that a technical problem has been reported at Swanwick air traffic control centre.