UK air traffic control glitch causes widespread flight cancellations and delays

Flight delays will continue on Wednesday after an air traffic control problem in the UK cancelled nearly 2,000 flights.

Tens of thousands of passengers were affected by the disruption which saw more than 1,750 flights cancelled on Tuesday and a further 153 axed on Wednesday, according to aviation analytics firm Cirium.

Nats, the air traffic control provider, blamed a technical glitch and its boss Martin Rolfe apologised, saying there would be a full investigation after the firm admitted resolving the issue had taken "longer than hoped".

Foreign Secretary Ed Miliband told the BBC the situation was "frankly unacceptable" and Transport Secretary Heidi Alexander has summoned Rolfe to a meeting to explain what happened.

Alexander will address the House of Commons on Wednesday about the disruption. She is expected to tell MPs that a cyber attack was "categorically" not the cause of the fault.

Flyers have been advised to continue to check with their airlines because it will take a while for flights to fully resume.

Heathrow has said passengers should only travel to the airport if they have a confirmed flight operating.

With few aircraft able to take off, it is understood landings were restricted, leading to some flights being unable to depart overseas airports.

The fault was widespread across the UK and beyond, with airports in Ireland also reporting disruption. EasyJet made 200 cancellations and British Airways more than 100.

It is not the first time disruption has blighted Nats' control system. In 2023, a computer shutdown over the August bank holiday weekend caused chaos for 700,000 passengers.

It took an engineer, who had been unable to correct the fault from home, three hours to get to work.

There was another, smaller Nats outage in 2025, which caused 150 cancellations.

Ryanair and Wizz Air have called for an overhaul of Nats, with Wizz Air saying it was "not fit for purpose" in its current form.

Yvonne Moynihan, managing director of Wizz Air UK, reiterated her calls for Rolfe to consider his position.

"I think in any position where you've had three failures you need to consider three strikes and your out," she told the BBC.

When asked whether he was considering his position, Rolfe said there would be "lots of time for that later" but his focus now was on making sure the problem was solved.

He said that despite the current situation, the UK generally had a very good air traffic system.

"Not to take away any of the frustrations and disappointment from people who haven't been able to travel, but we do have one of the best systems and one of the best services in the world and that's consistently recognised globally," he said.

Ryanair reported on Tuesday that more than 65,000 passengers had been delayed by up to eight hours.

At Heathrow, one of the busiest airports in Europe, departures were initially paused around lunchtime. Traffic then resumed, before facing further disruption in the afternoon.

It is understood the airport ran out of space for incoming flights during the afternoon because planes had not been departing - 13 Heathrow-bound flights were diverted to other sites in the UK and Europe.

A Heathrow spokesperson said on Wednesday its "operations are recovering".

"Flights are operating today, but we are expecting knock-on impacts as aircraft and crew reposition."

A London Gatwick spokesperson said: "Flights have now resumed from London Gatwick. However, we still anticipate that it will take time for our operations to fully return to normal."