UK Flight Data Glitch Cancels Thousands of Flights and Reignites Scrutiny of Air Traffic Provider NATS

A technical fault in the flight data processing system run by NATS, the UK's air navigation service provider, triggered widespread flight cancellations across British airports on September 8, with disruption continuing into the following day as airlines worked through the backlog. NATS said it ruled out a cyberattack as the cause; reporting has since pointed to a flight plan submitted by a UK military aircraft that introduced anomalous data into the system, though NATS has not confirmed a root cause publicly. When automated flight data processing goes down, controllers must build and manage flight data manually, which remains safe but far slower, so the only way to keep workload within safe limits is to sharply reduce the number of aircraft moving through the system, which is why airlines were required to cancel flights rather than simply absorb delays. Around 2,000 flights were cancelled in total, with Heathrow, Gatwick, Manchester and Birmingham among the worst-affected airports and roughly 15 UK airports affected overall; Ryanair alone said tens of thousands of its passengers faced delays of up to eight hours. The disruption prompted airline calls for NATS chief executive Martin Rolfe to resign, and the UK government gave NATS one week to investigate, while asking the Civil Aviation Authority to carry out an independent review, scrutiny sharpened by the fact this is the second major NATS flight-data failure in three years.