A technical failure in the UK's air traffic control system triggered mass disruption across British airports on Tuesday, with more than 1,100 flights cancelled and hundreds of thousands of passengers stranded or severely delayed. The fault, which began around 1pm, was traced to a flight processing system operated by NATS (National Air Traffic Services), the body responsible for managing airspace at 15 UK airports. NATS said it had resolved the issue by around 4:40pm, but warned that recovery would be complex and time-consuming, with the backlog of disrupted flights rippling well into Wednesday.

The airports worst affected included London Heathrow — the UK's largest and one of Europe's busiest — as well as Gatwick, Manchester, Birmingham, Edinburgh and Belfast. Heathrow suspended arrivals entirely for part of Tuesday evening, while 13 inbound flights were diverted to other UK and European airports. EasyJet cancelled around 200 flights, British Airways scrapped or diverted more than 100, and Ryanair — Europe's largest low-cost carrier by passenger numbers — reported that more than 65,000 of its customers faced delays of up to eight hours. The disruption extended beyond the UK: Amsterdam's Schiphol airport saw 58 UK-bound flights cancelled, KLM halted services to and from England, and Eurocontrol, the European airspace coordinator, confirmed that inbound flights across much of the continent were held at their departure airports.

NATS chief executive Martin Rolfe expressed his "huge sympathies" to affected travellers and confirmed that a full investigation would be launched. He acknowledged that recovery "took longer than we had hoped" but stressed the system involved was different from those that failed in previous major outages — in 2023, when more than 700,000 passengers were affected, and in a smaller incident the following year. Rolfe was scheduled to brief Transport Secretary Heidi Alexander on Wednesday, ahead of a parliamentary debate on the civil aviation bill. Alexander said she was "seeking assurances that lessons will be learned and that systems that support aviation are up to the job."

The incident reignited fury among airline executives. Ryanair's chief operating officer Neal McMahon renewed his call for Rolfe to resign, calling the failure "abhorrent" and urging the government to "appoint a new leader capable of running the UK ATC system." Wizz Air described NATS as "simply not fit for purpose in its current form." The disruption also had unexpected casualties beyond travel: Arsenal Football Club, scheduled to play Napoli in Italy in the Champions League on Wednesday, were forced to cancel a pre-match press conference after their flight was delayed.

This marks Britain's third significant air traffic control failure in just over three years, raising serious questions about the reliability of critical national aviation infrastructure. With 177 further flights already cancelled for Wednesday — almost all at Heathrow — the full scale of the disruption continued to unfold, and passengers were advised to check with their airlines before travelling to any UK airport.