Flight delays are expected to persist on Wednesday after an air traffic control issue in the UK resulted in nearly 2,000 flight cancellations. According to aviation analytics firm Cirium, more than 1,750 flights were cancelled on Tuesday, with an additional 153 cancellations reported on Wednesday. Nats, the air traffic control provider, attributed the disruptions to a technical glitch. Nats' CEO Martin Rolfe issued an apology and stated that a full investigation would take place, acknowledging that resolving the issue took longer than anticipated.
Foreign Secretary Ed Miliband described the situation as "frankly unacceptable," while Transport Secretary Heidi Alexander has called Rolfe to a meeting to discuss the incident. Alexander is set to address the House of Commons on Wednesday, where she will clarify that a cyber attack was "categorically" not the cause of the malfunction.
Passengers have been advised to check with their airlines for updates, as full flight operations will take time to resume. Heathrow Airport has advised travelers to only come to the airport if they have a confirmed flight.
Due to the limited number of aircraft able to take off, landings were restricted, affecting flights from overseas airports. The disruption was widespread, impacting airports in Ireland as well. EasyJet cancelled 200 flights, while British Airways cancelled over 100.
This is not the first instance of disruption linked to Nats' control system; in 2023, a computer shutdown during the August bank holiday weekend affected 700,000 passengers. An engineer took three hours to reach work to resolve the issue. A smaller outage occurred in 2025, leading to 150 cancellations.
Ryanair and Wizz Air have called for an overhaul of Nats, with Wizz Air's managing director Yvonne Moynihan suggesting that Rolfe should consider his position due to multiple failures. Rolfe stated that his priority is to resolve the current issue, emphasizing that the UK generally has a strong air traffic system.
Ryanair reported that over 65,000 passengers experienced delays of up to eight hours. At Heathrow, one of Europe's busiest airports, departures were paused around lunchtime but resumed later, although further disruptions occurred in the afternoon due to a backlog of incoming flights. Thirteen flights bound for Heathrow were diverted to other locations.
A spokesperson for Heathrow stated that operations are recovering, while London Gatwick confirmed that flights have resumed but warned that it may take time for normal operations to return. The worst affected airports included Heathrow, Gatwick, Manchester, and Birmingham. British Airways has indicated that it anticipates further knock-on effects from the disruptions.
Passengers have reported significant delays, with one individual stating that they were left sitting on the tarmac at Gatwick for hours due to the radar being down. Although Nats has resolved the issue with its flight processing system, backlogs are expected to continue affecting flight schedules.