Hundreds of flights to and from the UK are estimated to have been cancelled this bank holiday, leaving passengers stranded, after an air traffic control failure.
By Monday afternoon 232 flights departing UK airports had been cancelled and 271 arriving flights, according to aviation analytics firm Cirium.
This equates to about 8% of all expected departures and 9% of expected arrivals, Cirium added.
The technical fault meant flight plans had to be input manually by controllers.
National Air Traffic Services (Nats), the country’s leading provider of air traffic control, said at 3.15pm that it had “identified and remedied” the issue affecting its systems and was working with airlines and airports to support affected flights.
Juliet Kennedy, operations director at Nats, said the issue meant the automatic system that provides controllers with details of every aircraft and its route had stopped working, and what happened will be investigated “very thoroughly”.
Major UK airlines such as Tui and BA have warned of “significant delays” for passengers amid changes to schedules.
And Heathrow Airport said flights will remain disrupted for the rest of Monday, despite the technical issue being resolved.
The Nats statement added: “We are now working closely with airlines and airports to manage the flights affected as efficiently as possible.
“Our engineers will be carefully monitoring the system’s performance as we return to normal operations.
“The flight planning issue affected the system’s ability to automatically process flight plans, meaning that flight plans had to be processed manually which cannot be done at the same volume, hence the requirement for traffic flow restrictions.
“Our priority is always to ensure that every flight in the UK remains safe and we are sincerely sorry for the disruption this is causing. Please contact your airline for information on how this may affect your flight.”
Irene Franklin, 60, had her Delta flight from Heathrow to Austin, Texas – with her daughter, son-in-law and two friends – cancelled at the last minute.
She told the PA news agency outside Terminal 3: “It was (saying delayed by) two hours, now it’s cancelled. It’s now not until tomorrow morning at 10.
Air Traffic Control system update at 15:15 UK time—We have just published an update on our website – please read it here:https://t.co/YJO7NyZKxs
— NATS (@NATS) August 28, 2023
“It’s frustrating but what are you going to do?”
Asked if she had been offered compensation, she said: “No. Not for a place to stay tonight, not for a cab ride.
“The Delta customer service was really helpful, he got us on to the same flight with seats together but he didn’t really do anything else.
“We have a hotel booked but we have to pay for it and our meals.”
Daniela Walther, 44, was supposed to leave Heathrow for Stuttgart, Germany, on a BA flight at 5.25pm but it will now leave later than 1am.
The technical issue affecting @NATS has now been resolved.
Aviation Minister @CharlotteV and I are continuing to work with NATS to help them manage affected flights and support passengers.
All passengers should still contact their airline for specific flight information. https://t.co/IWgZJlXl91
— Mark Harper (@Mark_J_Harper) August 28, 2023
She said staff had been helpful but it “took a while to find someone to talk to”.
She added: “I know it’s going to be long but on the other hand I don’t dare to leave because I don’t want to miss information, and I don’t know if I don’t get it on my phone.”
A retired barrister who is stuck in Sardinia claimed an easyJet pilot said he had not seen an incident like this in 20 years.
Gemma Saleh, 43, who teaches part-time at law school and lives in Newcastle, told PA she boarded an easyJet flight with her family at 11.30am Sardinia time (10.30am London time), which was heading for Gatwick, and she remained on the plane for close to two hours.
She said: “We were told as we started to taxi there was an issue with the air traffic computer but he didn’t know more and we’d wait on the tarmac until we got a slot.
Some delays/cancellations likely to/from the UK today, 28 Aug due to UK ATC failure pic.twitter.com/dyAKoQHswq
— Ryanair (@Ryanair) August 28, 2023
“[The pilot] also said as we are ‘rescue’ we would be able to find a slot soon, maybe 30 mins.
“He’s not seen this in 20 years.”
Mrs Saleh, with her husband, a 43-year-old surgeon, and their two children, aged 10 and eight, and other passengers on the flight, were taken by bus back to the terminal to “wait it out there”.
She said easyJet provided free snacks and she is not sure when she will return home, with that flight having already been delayed since Sunday.
Transport Secretary Mark Harper said ministers were working with Nats to “help them manage affected flights and support passengers”.
He tweeted: “The technical issue affecting @NATS has now been resolved.
“Aviation Minister Charlotte Vere and I are continuing to work with NATS to help them manage affected flights and support passengers.
“All passengers should still contact their airline for specific flight information.”
Home Secretary Suella Braverman sympathised with anyone affected.
She told broadcasters: “I am very cognisant that this will disrupt people’s travel plans – those who are waiting to arrive in the UK, those waiting to depart, and I do sympathise with any disruption they may be experiencing.”