The National Air Traffic Services (NATS) of the UK released a preliminary report identifying a millisecond-level software glitch as the cause of the recent nationwide airport paralysis. The incident occurred on September 8, when a system responsible for assigning flight codes for radar identification failed. NATS CEO Martin Rolfe confirmed that the error originated in a specific module of the flight data system, specifically within a small snippet of code.
The disruption led to the cancellation of over 2,000 flights and affected hundreds of thousands of passengers across major hubs, including Heathrow, Gatwick, Manchester, Birmingham, and Edinburgh airports. Operations in Ireland also experienced interference. Heathrow Airport suspended departures around noon on September 8, with further delays occurring later that afternoon. NATS has implemented temporary mitigation measures while awaiting a permanent fix.
Following the incident, UK Transport Secretary Heidi Alexander held discussions with Martin Rolfe and demanded a comprehensive investigation. The UK Civil Aviation Authority has been tasked with conducting an independent review to verify the findings of the NATS report. Rolfe noted that this specific failure is unrelated to previous system issues recorded in August 2023 and July 2025. Public pressure has led to calls for the CEO to resign.
