More than 2,145 UK flights have been cancelled or disrupted since Tuesday after a technical failure struck National Air Traffic Services’ flight-processing system, with mounting calls for chief executive Martin Rolfe to resign as the government and aviation regulator launch separate investigations into the outage.
More than 2,145 flights arriving or departing the UK have been cancelled or otherwise affected since Tuesday, after a technical fault struck National Air Traffic Services’ (Nats) air traffic control systems. The disruption, which has affected an estimated 330,000 passengers, is expected to ease on Thursday as flight schedules gradually return to normal. Despite the anticipated recovery, pressure is mounting on Nats chief executive Martin Rolfe to resign, with Ryanair boss Michael O’Leary among those calling for him to step down, describing his position as “untenable” on Wednesday.
How the disruption unfolded
Cancellations and delays continued through Wednesday as airlines dealt with knock-on effects at major airports including Heathrow, Gatwick, Manchester and Stansted. Nats said the underlying technical fault, which affected its flight-processing system, was resolved at approximately 7.30pm on 8 September. However, the consequences continued well beyond that point, since the wider aviation network had effectively been knocked out of its normal operating position. Aircraft were diverted to airports including Paris, Edinburgh and Frankfurt during the failure, leaving planes and crews out of position and preventing an immediate return to normal service even after the technical issue itself had been fixed.
Heathrow was among the airports most severely affected, with more than 500 flights cancelled and arrivals temporarily suspended during the worst of Tuesday’s failure. The airport subsequently warned passengers that delays would persist even after flights resumed, as aircraft and crews continued to be repositioned.
Nats chief Martin Rolfe said there was no indication the failure was the result of a cyberattack, a position echoed by Transport Secretary Heidi Alexander, who told Parliament she did not believe the disruption stemmed from hostile cyber activity. Investigators are instead focused on the underlying technical and system failure, and specifically why the organisation’s redundancy arrangements failed to prevent such widespread disruption.
Government and regulator investigations launched
Transport Secretary Heidi Alexander met with Rolfe and has ordered a full investigation into what happened, with the government expecting a report within a week. Downing Street has said Rolfe retains the government’s confidence, despite growing calls from airlines for his resignation.
Separately, the Civil Aviation Authority (CAA) has been instructed to carry out an independent review of the incident, examining not only the technical cause of the failure but also whether Nats has sufficient resilience in place to prevent another large-scale disruption in future. That review is expected to report in around six months.
A disputed explanation
Nats has said the latest failure was distinct from the major incident in August 2023, involving a different problem with its flight-processing system. Ryanair, however, disputes this characterisation, arguing the latest failure was effectively another flight-plan processing breakdown, and claiming Nats has failed to deliver the backup resilience it promised following the 2023 meltdown. The dispute over Nats’ backup systems has become a major point of contention between the airline and the air traffic provider, with the key unresolved question being whether the backup system failed outright, was unavailable, or simply could not handle the scale of disruption when called upon.
A pattern of repeated failures
The latest crisis marks the third major Nats disruption in just a few years. A significant failure in August 2023 caused widespread cancellations and reportedly affected around 700,000 passengers, while a further technical and radar problem in July 2025 disrupted several major UK airports. Airlines argue this recurring pattern strengthens the case that the latest failure is not simply an isolated technical accident.
Financial fallout
Ryanair said the disruption had cost the airline approximately £3 million by the time of its latest statement, after cancelling around 260 flights and affecting roughly 48,000 passengers. The airline is separately pursuing a legal claim against Nats over the 2023 outage, seeking more than £7 million in damages.
The wider aviation industry faces a broader range of costs stemming from the latest disruption, including cancelled flights, aircraft repositioning, crew displacement, hotel accommodation, passenger assistance, missed connections, and lost revenue, with the full economic impact unlikely to become clear until airlines complete their calculations.
Adding further controversy, Nats paid approximately £175 million in dividends to its owners in 2025, a figure that has prompted Ryanair and other industry representatives to question whether more of the organisation’s resources should be directed toward system resilience, staffing and infrastructure investment rather than shareholder returns.
Industry criticism grows
Ryanair is not alone in its criticism of Nats. Wizz Air has also called for urgent reforms in the wake of the latest failure, while trade body Airlines UK has separately complained that airlines are left bearing much of the financial burden of providing passengers with accommodation, rebooking and other assistance, even when the underlying disruption originates with Nats rather than the airlines themselves.
What compensation passengers can expect
The CAA has indicated that the Nats failure is likely to qualify as an “extraordinary circumstance” under passenger rights rules, meaning passengers will generally not be entitled to standard fixed compensation for delays or cancellations directly caused by the outage.
Airlines nonetheless retain other obligations towards affected passengers. Depending on individual circumstances, these can include the provision of food and refreshments, clear communication, accommodation where an overnight stay becomes necessary, transport to that accommodation, rebooking onto an alternative flight, or a refund for passengers who choose not to travel at all.
