Air passengers faced a second day of disruption on Wednesday as flights continued to be cancelled following a technical glitch with the UK's traffic control system.

Tens of thousands of people saw their travel plans upended as airlines cancelled 327 flights, according to aviation analytics firm Cirium, after 1,750 flights were axed on Tuesday after the problem emerged.

Nats, the air traffic control provider, apologised and said on Wednesday afternoon its operations were "stable". It promised an investigation into what is its third major technical fault in three years.

The government said Nats' boss has its confidence though Foreign Secretary Ed Miliband said the outage was "unacceptable".

Martin Rolfe, who has led Nats for 11 years, met with Transport Secretary Heidi Alexander on Wednesday morning where she "significant concerns" about the widespread disruption.

Downing Street said Nats - which is 49% owned by the government - must report back in one week detailing what went wrong during Tuesday's incident.

Flyers have been advised to continue checking flights with their airlines as it is expected it will take days for schedules to return to normal.

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

A glitch with Nats' flight processing system early on Tuesday afternoon led to airlines having to cancel scores of flights both to and from the UK.

According to FlightRadar, the worst affected airports were Heathrow, Gatwick, Manchester and Birmingham.

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

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."

At Gatwick, a 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."

Manchester, Luton, Stansted, Bristol, and Belfast City Airports all said on Wednesday that flights had resumed. Although Bristol, Belfast and Luton said there continued to be knock-on effects.

What are my rights if my flight is cancelled or delayed?

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, who has been in charge of Nats since May 2015, to consider his job.

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

Rolfe was paid £1.4m for the year ended 31 March, including a £343,000 bonus.

Asked about his future in charge of the company, Rolfe told the BBC there would be "lots of time for that later" but his focus now was on making sure the problem was solved.

Nats is a public-private partnership, with the government holding the majority stake. The rest is split between a group of UK airlines including BA, easyJet and Virgin Atlantic as well as Heathrow and Nats staff.

Rolfe 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.

However, Doug Maclean, Nats' former air traffic control manager, told the BBC that the system's technological excellence was undermined by repeated outages.

"You've got a world-leading system where the wheels fall off every now and again," he said.

Phil White was left sitting on a plane at Gatwick for hours

Phil White from Bexhill told BBC Your Voice that his flight to Lanzarote boarded on time but he was left sitting on the tarmac at Gatwick for hours.

"We've been told the radar is down and we can't take off," Phil said on Tuesday.

"It's comfortable enough but the pilots been on every 20 minutes saying they are waiting for information from air traffic control and when he finds anything out he will let us know."

Even if Nats has resolved the issue with its flight processing system, the disruption is likely to persist due to backlogs.

Rolfe said the issue was in Nats' flight data processing system. He said it was not the same system that failed during the incident in 2023.

Although the technical issue affected departures, arrivals were also hit as space on the ground became increasingly restricted.

Additional reporting by Emer Moreau, Faarea Masud and Nick Watt

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