London: More than 1,000 flights to and from airports across the United Kingdom were cancelled after a major technical failure hit the country’s air traffic control system, triggering widespread disruption at some of Britain’s busiest airports.

The fault affected the flight processing system operated by National Air Traffic Services (NATS), disrupting departures and arrivals across the country on Tuesday. NATS later said the technical issue had been fixed and operations had returned to normal, although clearing the backlog was taking longer than initially hoped.

Heathrow, Britain’s largest and busiest airport, was among the major hubs affected, along with Gatwick, Birmingham, Liverpool, Edinburgh, Manchester and several other airports. Dublin Airport in Ireland also reported dozens of cancellations as the disruption spread beyond the UK.

Airlines were forced to cancel, delay or divert scores of services as aircraft and crews were left out of position.

British Airways said it had cancelled or diverted more than 100 flights, affecting tens of thousands of passengers. The airline warned that the scale of the disruption would continue to have a knock-on impact even after the technical fault had been resolved.

Irish low-cost carrier Ryanair said more than 65,000 passengers were affected, with some facing delays of up to eight hours. The airline cancelled more than 50 flights because of the disruption.

NATS said engineers had identified the problem within its flight processing system and implemented a fix, but acknowledged that restoring normal schedules across the aviation network would take time.

The latest breakdown has renewed concerns over the resilience of Britain’s air traffic control infrastructure.

A similar technical failure in July 2025 resulted in more than 120 flight cancellations across UK airports, with disruption continuing into the following day at Heathrow.