NATS outage cost UK aviation industry £33 million, report finds

A major air traffic control outage in September cost UK aviation businesses an estimated £33 million, according to a new report.

The Cyber Monitoring Centre (CMC) says the technical failure at National Air Traffic Services (NATS) on 8 September affected more than 70 UK organisations.

More than 2,000 flights were cancelled as a result of the incident, hundreds of thousands of passengers were affected.

Now, the CMC’s report, published on 4 November, estimates financial losses of £33 million.

The figure includes costs to UK airlines, airports, ground operations and tour operators from cancellations, delays and diversions.

CMC said that when it also covered the impact on overseas airlines, the estimated final impact was between £48 million and £76 million.

Airlines bear most of £33 million NATS outage cost

According to the report, airlines absorbed more than three-quarters of the financial impact. In contrast, it estimated that NATS itself incurred less than £1 million in lost route charges or cancelled flights.

The CMC’s UK estimate accounts for 1,152 cancelled flights, alongside significant delays and diversions.

The report found that the disruption affected around 450,000 passengers through cancellations or delays of at least two hours.

Despite the scale of disruption, the incident was classified as a Category 1 event – the lowest level on the CMC’s five-point financial impact scale.

The organisation said it was caused by a “previously unknown defect in legacy software” and “was not malicious”.

The report stated: “Like the CrowdStrike software failure in 2024, it nonetheless shows how a failure in a single critical technology can cause widespread disruption to UK organisations.

“Its significance lies less in the scale of loss than in what it shows about the aviation system: a brief outage in a single critical system disrupted airline schedules for several days, and almost all of the cost fell on airlines and other organizations rather than on NATS.”

Recommendations from CMC

The report includes three recommendations for the aviation industry – including planning for a “multi-hour restriction in air traffic capacity”.

It also recommended reviewing coordination between NATS, airlines and airports during major outages.

CMC technical committee chair, Ciaran Martin said: “Organisations need to understand and plan for the risks that sit in systems they depend on, not just the systems they own.”

The CMC warned that the risk of outages stemming from unidentified software defects “is heightened while NATS continues to rely on legacy systems.”