Technical Fault Forces Cancellation of Nearly 1,100 UK Flights

A major technical failure in the UK’s air traffic control system triggered widespread travel disruption on September 8, forcing the cancellation of more than 1,000 flights and leaving thousands of passengers facing delays, diversions and missed connections.

A technical fault affecting Britain’s air traffic control network caused severe disruption at airports across the country, with 1,055 flights cancelled by 7:00 PM GMT on Tuesday, September 8, according to flight-tracking data cited by aviation authorities.

The disruption affected flights both arriving at and departing from the UK, creating significant problems for passengers at some of the country’s busiest airports.

What Caused the Disruption?

The problem originated with NATS, the organisation responsible for providing air traffic control services across much of the UK.NATS said the technical issue affected its flight data processing system. The provider later confirmed that the fault had been resolved and stressed that aviation safety had not been compromised.

However, restoring the system did not immediately return flight operations to normal.

NATS acknowledged that recovery had taken longer than expected because of the complexity of restarting operations and clearing the backlog of aircraft waiting to depart or arrive.

Heathrow, Gatwick and Other Airports Hit

Among the airports affected were major hubs including:

•    London Heathrow
•    London Gatwick
•    Manchester
•    London Stansted
•    London City
•    Luton
•    Edinburgh
•    Bristol
Heathrow suspended arrivals for the remainder of Tuesday evening at one stage, while departures gradually resumed. Passengers were warned that delays and cancellations could continue even after the air traffic control system returned to normal.

The effects also extended beyond Britain. Dublin Airport reported dozens of cancelled arrivals and departures because many Irish services depend on UK airspace.

Cancellation Numbers Continued to Rise

Early reports placed the number of cancelled flights at nearly 1,100, with 1,055 cancellations recorded by Tuesday evening.

Later data showed the scale of the disruption had grown further.

Flightradar24 data cited by Reuters indicated that around 1,300 flights to and from UK airports were ultimately cancelled on Tuesday, with additional cancellations scheduled for Wednesday as airlines attempted to restore their networks.

By September 9, aviation analytics company Cirium estimated that approximately 2,000 flights across Tuesday and Wednesday combined had been affected by cancellations linked to the outage and its knock-on effects.

Aircraft and crews being left in the wrong locations after Tuesday’s disruption made it difficult for airlines to immediately return to their normal schedules.

Airlines Criticise NATS

Several major airlines reacted strongly to the outage.

Ryanair said tens of thousands of its passengers had been affected and called for changes at NATS, while Wizz Air also urged reforms to improve the resilience of Britain’s air traffic control infrastructure.

British Airways was also heavily affected, cancelling or diverting around 100 flights on Tuesday and cancelling further services on Wednesday as operations recovered.

The incident renewed scrutiny of NATS following previous major technical problems affecting UK air travel.

A significant flight-plan processing failure in August 2023 caused widespread disruption, while another radar-related technical issue affected flights in July 2025.

Government Orders Investigation

The UK government has asked NATS to establish exactly what went wrong.

Transport Minister Heidi Alexander summoned NATS chief executive Martin Rolfe for talks and said the provider had been given one week to report on the incident.

Alexander said the outage was not believed to have been caused by a cyberattack and also announced an independent review by the UK Civil Aviation Authority, which is expected to examine the cause of the failure and the resilience of the country’s air traffic control systems.

NATS has said it will conduct a full investigation into the root cause.

What Should Affected Passengers Do?

Passengers with upcoming UK flights are being advised to check directly with their airline before travelling to the airport, as schedules may continue to change while aircraft and crews are repositioned.

Under UK passenger-rights rules, travellers whose flights are cancelled should generally be offered either:

•    An alternative flight or rebooking
•    A refund if they choose not to travel

Airlines may also be required to provide reasonable assistance such as food, accommodation and transport where necessary.

However, passengers may not automatically qualify for additional cash compensation if the disruption is deemed an “extraordinary circumstance” outside the airline’s control, according to the Civil Aviation Authority.

Travellers should keep receipts for reasonable expenses and check their airline’s policies or travel insurance coverage.

Disruption Highlights Aviation System Vulnerability

The incident demonstrates how quickly a technical problem within air traffic control can spread across a heavily interconnected aviation network.

Even after the original fault is fixed, cancelled flights can leave aircraft and crews hundreds or thousands of kilometres from where they are needed for subsequent journeys.

While normal air traffic operations have resumed, passengers may continue to experience residual disruption as airlines rebuild their schedules.

Anyone travelling through a UK airport in the immediate aftermath of the outage is advised to monitor flight status closely before leaving for the airport.