A technical failure affecting the UK’s air traffic control system has caused widespread delays and cancellations, disrupting tens of thousands of passengers and leaving airlines facing a lengthy recovery operation.
Hundreds of flights have been cancelled and many more delayed after a technical failure struck the computer system used by the UK’s air traffic control provider, NATS.
The problem developed during the early afternoon of Tuesday, September 8, severely restricting the number of aircraft able to depart from airports across the country.
NATS first acknowledged the disruption at 1.46pm, saying its engineers were investigating a technical issue affecting flight departures. It subsequently traced the fault to its flight-processing system.
Although UK airspace remained open and some flights continued to operate, traffic-flow restrictions were introduced as controllers managed aircraft at a reduced rate.
At 4.40pm, NATS announced that it had implemented a fix and that the affected system was beginning to recover.
“We apologise sincerely for the disruption to people’s journeys today,” the company said, while warning passengers to continue checking their flight status with their airline.
Hundreds Of Flights Cancelled
By early Tuesday evening, approximately 300 flights had been cancelled across the UK, according to Flightradar24 data reported by the Associated Press.
London’s airports were among the worst affected. Most departures from Heathrow, Gatwick, Stansted and London City were either delayed, cancelled or held on the ground during the height of the failure.
FlightAware data cited by Reuters showed around 100 cancellations and 367 delays at Heathrow. Approximately 250 flights were delayed at Gatwick, representing almost a third of the airport’s scheduled operations.
Disruption was also reported at Manchester, Birmingham, Bristol, Luton, Edinburgh, Glasgow, Aberdeen and Belfast. Flights serving Dublin and other European airports were affected as aircraft were held before departing for the UK.
British Airways confirmed that its operation had been disrupted, while easyJet said the failure was causing delays across its wider European network.
Ryanair claimed that more than 65,000 of its passengers had been delayed and that it had cancelled 50 flights because of the restrictions.
Airlines Demand NATS Overhaul
The latest failure has renewed criticism of NATS following several serious technical incidents.
A major breakdown in August 2023 prevented the automatic processing of flight plans and caused widespread disruption over several days. An independent review subsequently estimated that the incident affected around 700,000 passengers and cost airlines up to £100 million.
Another technical problem, involving a radar system at NATS’ Swanwick control centre, disrupted flights for more than four hours in July 2025.
Following Tuesday’s failure, Wizz Air called for an overhaul of NATS, while Ryanair renewed its demand for chief executive Martin Rolfe to resign.
The UK Civil Aviation Authority said it had contacted NATS and expected the company to provide a full report. The regulator will then consider whether further action is required to protect the safe and reliable operation of the country’s air traffic control system.
NATS has not yet disclosed the underlying cause of Tuesday’s failure beyond confirming that it affected its flight-processing system.
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