Passengers have been urged to check flight information with their airlines after an air traffic control issue caused disruption to all UK airports on Wednesday.

Some passengers have reported delays, and one travel expert told the BBC the disruption could last for days.

Airlines are demanding answers after more than 150 flights were cancelled on Wednesday and thousands more were grounded.

The air traffic control provider NATS, which has apologised, said it had taken 20 minutes to resolve the issue by switching to a back-up system, and systems were fully operational within an hour.

Transport Secretary Heidi Alexander met NATS chief executive Martin Rolfe on Thursday morning to get further detail on what had happened.

Following the meeting she acknowledged that disruptions were “frustrating for passengers”, and she was receiving regular updates.

“This was an isolated event and there is no evidence of malign activity,” she said on X. “Passengers should check with airlines before travelling.”

A Heathrow Airport spokesperson said the airport was operating normally on Thursday. According to the airport’s website, 10 flights on Thursday morning to and from the airport were cancelled – four departures and six arrivals.

Flights at other major UK airports were returning to normal on Thursday morning.

Stansted Airport said all flights were operating as normal on Thursday morning, while a Gatwick Airport spokesperson said operations were “stable”.

At Manchester Airport, three outbound and three inbound flights were cancelled but a spokesperson for the airport said they were being worked into the schedule without affecting other flights.

Ryanair also said all flights were operating as usual on Thursday.

Airports across the UK urged passengers to check their flight status with their airline following Wednesday’s disruption.

Under UK law, airlines have a duty to look after passengers if flights are delayed or cancelled, including providing meals and accommodation, if necessary, and getting people to their destination. The airline should also organise an alternative flight at no extra cost.

However, disruption caused by things such as a fire, bad weather, strikes by airport or air traffic control staff, or other “extraordinary circumstances” does not entitle passengers to extra compensation.

Vicki Sluce and her husband David are stuck in Antalya in Turkey with their two children after EasyJet cancelled their flights.

Vicki says the airline has blamed the NATS outage for the delay and has said it cannot fly them back to the UK until Saturday evening.

“I’m stressed out,” says Vicki. “I don’t want it to affect the kids. My daughter spent three hours crying and has thrown up from stress thinking she’s stuck in Turkey.”

Travel expert Simon Calder told BBC Breakfast there would be “thousands of people who are waking up where they did not expect to be this morning”.

He warned that disruption from Wednesday’s outage would continue in the coming days as airlines attempt to get stranded passengers, as well as planes and crew, to their intended destinations during the busy summer holiday schedule.

“The trouble is, at this time of year everything is stretched, all the airlines are running to maximum efficiency, very little slack in the system, very few spare seats to accommodate passengers whose flights were cancelled in the hundreds,” he said.

According to aviation data firm Cirium, 84 departures and 71 arrivals were cancelled across all UK airports on Wednesday evening. That equates to 3% of all departures and 2% of all arrivals.

Cirium does not attribute causes for cancellations, but confirmed Wednesday evening’s cancellations were above average.

On Thursday morning, 12 departures and 11 arrivals had been cancelled by 08:30 BST, but Cirium said it was too early to say if those were outside the normal range.

According to NATS, the Wednesday afternoon issue was “radar-related” and it reduced flight traffic to ensure safety. It added there was no evidence the incident had been cyber-related.

EasyJet’s chief operating officer, David Morgan said the error was “extremely disappointing”, while a Ryanair executive called for NATS chief executive Martin Rolfe to resign.

Ryanair executive Neal McMahon said it was clear “no lessons” had been learnt and passengers continued to “suffer” as a result of Mr Rolfe’s “incompetence”.

In August 2023, more than 700,000 passengers were affected by the cancellation of more than 500 flights at the UK’s busiest airports due to a major outage.

EasyJet’s chief operating officer, David Morgan, said: “It’s extremely disappointing to see an ATC failure once again causing disruption to our customers at this busy and important time of year for travel.”

Graham Lake, a former director general of the Civil Air Navigation Services Organisation, told the BBC’s Today programme it was not fair to call for the boss of NATS to resign over the failure, as the organisation got the system back up and running “as safely and quickly as it could”.

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