Air travel in the UK has been disrupted after air traffic control systems suffered a “technical fault” on Monday morning.
The issue was “identified and remedied” around 3.30pm on Monday – but that doesn’t mean a swift end to disruption.
Here’s what we know so far.
What is the fault?
NATS, the National Air Traffic Controllers said it had “identified and remedied” the technical issue affecting its flight planning system.
“We are now working closely with airlines and airports to manage the flights affected as efficiently as possible,” it said in a statement.
“Our engineers will be carefully monitoring the system’s performance as we return to normal operations.”
The fault had affected the system’s ability to automatically process flight plans, which means they had to be inputted manually by staff.
As this cannot be done at the same speed, traffic flow restrictions had to be enforced.
Earlier on Monday NATS said it had been hit by a “technical issue” but said the UK’s airspace was “not closed”.
They reduced the number of aircraft that could take off and land at a given time to manage flow.
What’s happening to flights?
For passengers, the changes to traffic flow restrictions means delays and possible cancellations.
Flights were being held on the tarmac or diverted to airports in Ireland or mainland Europe, travel journalist Simon Calder told Sky News.
“There are hundreds of planes up in the sky heading to the UK,” he said – meaning hundreds of thousands of passengers could be affected.
The August bank holiday is one of the busiest days of the year for air travel.
Mr Calder said some flights would be able to land as air traffic controllers switched from digital to “much more analogue” systems, but the rate would be much slower.
How long could the disruption last?
Even if the issue was fixed quickly, the system would likely be in “disarray” for at least the rest of Monday and possibly longer, Mr Calder said.
Aviation analyst and former BA pilot Alastair Rosenschein told Sky News it was “very difficult” to say when things would be back to normal.
But he offered some reassurance, saying the disruption looked to be “delays of hours rather than anything longer”.
He said the issues appeared to be a case of “patchy failure rather than total shutdown”.
Which airports are reporting disruption?
Airlines have released similar statements while they assess the likely impact of the situation.
Dublin Airport said there were some delays to flights in and out of the airport due to Air Traffic Control issues in the UK
“We advise all passengers due to travel today to check the status of their flight with their airline in advance of travelling,” it said.
Ireland’s Cork Airport has said the air traffic control issues are causing delays for some departing and arriving flights.
Gatwick Airport has warned cancellations are “likely” and it is “seeing delays”, after earlier saying flights were running as normal.
Luton Airport says: “We are aware of an air traffic control issue affecting UK airspace, resulting in disruption to flights.
“We are working with all relevant authorities to understand the full impact of the issue and when normal operations are likely to resume.
“Passengers should check with their airline for the latest status of their flight.”
Birmingham Airport says: “We are working to understand the full impacts of the air traffic control failure across UK airspace, and the likely timescales for to be resolved.
“Customers due to fly in or out of BHX are advised to keep a close eye on the latest information from their airlines, as well as live flight data on our website and on screens in our terminal.”
Heathrow Airport says it is “working closely” with NATS and other airports to “minimise the impact” on passengers. ‘
Stansted Airport says it is “fully operational” and is not experiencing any issues.
Liverpool John Lennon Airport warned of disruption, saying: “Whilst aircraft will be loaded on time, some flights may be subject to a delay.”
Newcastle International Airport says passengers face “disruption” and “some cancellations”.
Edinburgh Airport asks passengers “not [to] come to the airport before checking with their airline on the status of their flight”.
What are airlines saying?
Scottish airline Loganair, one of the first to report disruption, said there was a “network-wide failure of UK air traffic control computer systems” on Monday morning.
“Although we are hopeful of being able to operate most intra-Scotland flights on the basis of local coordination and with a minimum of disruption, north-south and international flights may be subject to delays,” the airline posted on X, formerly known as Twitter.
It urged passengers to check its website for updates.
British Airways said it had been forced to make “significant changes” to its bank holiday schedule.
“If you are travelling on a short-haul service today, Monday August 28, please do not travel to the airport without checking the status of your flight, as it may no longer be operating,” the airline said.
EasyJet said: “We are providing customers on cancelled flights with the option to transfer their flight free of charge or receive a refund.”
What should I do if I’m travelling?
If you’re due to fly in or out of the UK today, check the status of your flight with your airline – this is what each airport and airline is currently advising.
If you’re already at the airport, keep an eye on display screens.
This article will continue to be updated with all the latest information you need if you’re due to travel.
You can also follow our live blog which will have updates on what’s going on.
What are my rights if my flight is delayed?
Disruption to air traffic control counts as an “extraordinary circumstance”.
That means it is out of the airline’s control – so they don’t have to offer compensation.
But if your flight is delayed by two hours or more, airlines must offer assistance under UK law.
They have a duty to provide:
• two free phone calls, faxes or emails (often by refunding the cost of your calls)
• free meals and refreshments appropriate to the delay (often in voucher form)
• free hotel accommodation and hotel transfers if an overnight stay is required.
Sometimes airlines may be unable to provide assistance to all passengers, particularly where staff are stretched – which could be the case with the mass delays seen today.
If this is the case, the Civil Aviation Authority says passengers should organise their own assistance and claim the cost back later.
“If you end up paying for things yourself, keep every receipt and do not spend more than is reasonable,” its website says.
It cautions airlines are unlikely to reimburse for alcohol or luxury hotels. Some airlines provide guidelines on what counts as reasonable expenses.