Passengers face further disruption at Heathrow, Gatwick and other airports after major Nats system failure leaves aircraft and crews stranded out of position.
Hundreds of flights have been cancelled across Britain as disruption caused by a major air traffic control system failure entered a second day.
Airlines were attempting to rebuild their schedules on Wednesday morning after a technical fault at National Air Traffic Services, Nats, caused widespread disruption on Tuesday, grounding flights and leaving passengers stranded in Britain and across Europe.
Flight tracking service Flightradar24 reported that around 1,300 flights to and from UK airports were cancelled on Tuesday. By Tuesday night, at least another 177 flights scheduled for Wednesday had already been cancelled, with the majority of those at Heathrow. Further cancellations were being announced as airlines dealt with the aftermath of the failure.
Heathrow has warned passengers to check the status of their flight with their airline and only travel to the airport if it is confirmed as operating. Gatwick said flights had resumed on Wednesday morning, although passengers were warned that it would take time for normal operations to be restored.
The disruption began shortly after 1pm on Tuesday, when Nats experienced a problem affecting its flight data processing system. The failure severely restricted departures at some of the country’s busiest airports, including Heathrow, Gatwick, Manchester and Stansted.
Nats said the problem had been resolved on Tuesday evening and stressed that safety had not been compromised. However, the organisation acknowledged that recovery had been more complicated than hoped and warned that disruption across the aviation network would take time to clear.
The consequences continued long after the computer system itself was restored. Aircraft had been diverted or left at airports where they were not scheduled to be, while pilots and cabin crew were also left in the wrong locations. Airlines therefore faced the task of repositioning both aircraft and staff before normal timetables could resume.
British Airways said it had been forced to cancel or divert more than 100 flights during Tuesday’s disruption and warned customers that there would be significant knock-on effects. Ryanair said more than 200 of its flights had been cancelled and around 150,000 passengers affected by delays and disruption.
The incident has also intensified pressure on Nats and its chief executive, Martin Rolfe.
Ryanair’s chief operating officer, Neal McMahon, publicly called for Mr Rolfe to resign, while Wizz Air said the latest failure demonstrated the need for urgent reform of Britain’s air traffic control provider. Wizz Air described Nats as “not fit for purpose in its current form”.
Mr Rolfe is due to speak to Transport Secretary Heidi Alexander on Wednesday as the Government seeks answers over what caused the latest breakdown. He told Sky News that Nats had not yet completed its investigation into exactly what went wrong.
Asked about his own responsibility for the disruption, Mr Rolfe said he accepted full responsibility as the chief executive of an organisation responsible for critical national infrastructure, but indicated that his immediate priority was dealing with the incident and its aftermath.
The latest failure is particularly significant because it follows other serious problems with Britain’s air traffic control infrastructure in recent years.
During the August bank holiday in 2023, a failure in Nats’ automated flight-plan processing system caused widespread disruption. A subsequent review by the Civil Aviation Authority found that the incident affected more than 700,000 passengers, while airlines said the financial impact ran to more than £100 million.
Another technical problem in July 2025, this time involving a radar-related system, disrupted flights for more than four hours at major airports, including Heathrow.
The repeated failures have now prompted renewed questions about the resilience of Britain’s air traffic control infrastructure and whether sufficient safeguards are in place to prevent a single technical problem causing disruption on such a large scale.
The Civil Aviation Authority has said it expects Nats to provide a full report into Tuesday’s incident. The regulator will then consider whether further action is required to ensure the reliability of the country’s air traffic control system.
For passengers, however, the immediate concern remains whether their flights will operate.
Heathrow is advising travellers to check directly with their airline before setting off for the airport, warning that disruption is continuing while airlines work to restore their schedules.
Even with the Nats system operating normally again, the scale of Tuesday’s cancellations means the effects could continue as airlines attempt to get thousands of passengers, aircraft and crew members back to where they should be.
