More than 2,000 flights affected as UK recovers from NATS system failure

Disruptions continued at airports across the United Kingdom on Wednesday, 9 September, after NATS’ flight-processing system failed a day earlier. Although the technical problem has been resolved and air traffic services are operating normally, airlines are still repositioning aircraft and crews.

According to aviation analytics company Cirium, more than 2,000 flights were cancelled or failed to operate across Tuesday and Wednesday, affecting an estimated 300,000 passengers. Around 1,750 flights were cancelled on Tuesday alone, representing approximately 30% of the day’s scheduled operations, compared with a typical cancellation rate of 1–2%.

Hundreds more flights were cancelled on Wednesday, with London Heathrow particularly badly affected. British Airways recorded the largest number of cancellations as it tried to restore operations at its main hub. London Gatwick and other UK airports warned that residual delays and cancellations could continue and advised passengers to confirm their flight before travelling.

NATS said the failure began at 13:46 BST on Tuesday and affected its flight-processing system. A fix was implemented at 16:40, but the subsequent recovery proved more complex and lasted longer than expected. The provider stressed that the latest fault was unrelated to the major August 2023 outage, while chief executive Martin Rolfe ruled out a cyberattack.

UK Transport Secretary Heidi Alexander summoned Rolfe to explain the incident and ordered NATS to submit an initial investigation report within one week. The government said it continued to have confidence in him, despite renewed calls from Ryanair and other airlines for his resignation and a wider overhaul of the air traffic control provider. The UK Civil Aviation Authority has also requested a full incident report and will assess whether further action is required.

The failure has again raised questions about the resilience of the UK’s air traffic management infrastructure, following major technical disruptions in 2023 and 2024.

Sources: Cirium, Sky News, NATS, Reuters