A technical failure in the United Kingdom’s air traffic control system disrupted hundreds of flights across major airports Sept. 8, triggering widespread cancellations and delays that continued after the system began recovering.

NATS, the country’s air traffic control provider, identified the problem in its flight processing system and implemented a fix. The organization said it was working with airline and airport customers to restore normal operations, but warned that recovery would take time.

The disruption affected airports including Heathrow, Gatwick, Manchester, Birmingham, Edinburgh and several other UK facilities. Airlines also reported knock-on effects across Europe as aircraft and crews were displaced from their scheduled rotations.

According to the Associated Press, flight-tracking data showed at least 625 flights to and from UK airports had been canceled. British Airways, easyJet, KLM and Lufthansa were among the carriers affected.

Ryanair said more than 65,000 of its passengers experienced delays of up to eight hours and that it had canceled more than 50 flights. British Airways also reported significant disruption, with aircraft and crews ending up out of position.

NATS apologized for the disruption and advised passengers to check their flight status directly with their airlines.

The UK Civil Aviation Authority said it expects NATS to provide a full report on the incident and will consider whether additional steps are needed to improve the reliability of the air traffic control system.

The failure renews scrutiny of NATS following a major flight-plan processing outage in August 2023, which prompted an independent review and recommendations concerning system resilience and contingency planning. A separate radar-related technical issue also disrupted flights in July 2025.

The cause of the Sept. 8 fault had not been publicly established as of the latest reports.