More than 2,000 flights were cancelled at UK airports on Tuesday, September 8, 2026, after the NATS air traffic control system shut down for approximately four hours, causing widespread delays, diversions, and groundings across the country’s aviation network.
Cause of the Disruption
The shutdown was triggered when spurious flight data submitted by a UK military aircraft overwhelmed NATS’ flight-processing system. The system lacked a dedicated backup for this critical component, and attempts to restart the system took several hours and multiple tries before success.
Scope and Immediate Impact
At least 15 UK airports were affected, among them Heathrow, Gatwick, and Manchester. British Airways cancelled nearly 550 flights alone
due to the disruption. The shutdown caused significant operational challenges, including cancellations, delayed departures, and arrivals diverted to other international airports.
Operational Consequences
The outage not only halted flights but also disrupted aircraft and crew positioning, resulting in backlog issues that prompted further cancellations beyond the initial disruption. Some passengers remained onboard grounded aircraft for hours, while the system’s failure impeded effective traffic movement across the UK aviation network.
Official Statements and Investigations
NATS Chief Executive Martin Rolfe described the event as unprecedented in his 50 years of operation, stating: “We believe we’ve never seen an incident happen more than once, so this will be something
different that we’ve never seen in 50 years of operation.” Transport Secretary Heidi Alexander called the incident avoidable and demanded a detailed report from NATS within a week. The Ministry of Defence said there was no indication of error on the part of the military and declined further comment while NATS’ investigation remains ongoing. Meanwhile, the Civil Aviation Authority is conducting an independent inquiry and has requested a technical report from NATS.
Ryanair CEO Michael O’Leary criticized NATS management harshly, asserting: “We don’t need more investigations, we don’t need more reports, and we don’t need another parliamentary committee hearing where
Martin Rolfe will promise change, will promise resilience and will promise an effective backup system.” Both Ryanair and Wizz Air have called for substantial structural changes at NATS following repeated system failures in 2026.
Context and Industry Impact
This incident follows a serious NATS outage in August 2023 that affected approximately 700,000 travellers and prompted 34 recommendations by the Civil Aviation Authority. NATS has stated those recommendations have been implemented. The recurrence of such large-scale disruptions has raised concerns among industry stakeholders about the resilience and backup capabilities of the UK’s air traffic control infrastructure.
