LONDON, Sept. 19 (Xinhua) -- A software defect lasting only a fraction of a second triggered a major failure in Britain's air traffic control system earlier this month, leading to more than 2,000 flight cancellations, the country's air navigation service provider said Friday.
In an initial report on the Sept. 8 incident, the National Air Traffic Services (NATS) said the defect occurred "in the space of a millisecond" and caused corrupted data in a system supporting the management of British airspace.
With controllers receiving reduced information, restrictions were imposed on air traffic to ensure safety. The disruption involved major airports including Heathrow, Gatwick, Luton and Glasgow, affecting hundreds of thousands of passengers and taking several days to fully clear.
NATS Chief Executive Martin Rolfe described the defect as "very, very obscure" and apologized to passengers. He said aviation safety had not been compromised during the incident.
British Transport Secretary Heidi Alexander called the disruption "completely unacceptable" and said that a review by the Civil Aviation Authority was underway to examine why the defect had not been detected and resolved earlier.
Airlines UK, a British aviation industry body, said it would seek compensation from NATS for costs incurred by carriers and called for stronger safeguards against future failures.
The incident was Britain's third national air traffic control disruption in three years. A major system failure in August 2023 affected about 700,000 passengers, while another outage in 2025 led to around 150 flight cancellations. ■