U.K. Air Traffic Control Rules Out Cyber Attack After Software Issue Disrupts Flights

The head of U.K. air traffic control services has said he does not believe a cyber attack caused the software issue that disrupted hundreds of thousands of passengers with flight cancelations on Tuesday.

"Obviously we will be doing a very thorough and full investigation. We have at this point ruled out cyber, we don't believe it was a cyber attack," Martin Rolfe told BBC Radio 4's Today program on Wednesday.

"I don't believe we've ever seen an incident happen more than once, so this will be something different that we've never seen in 50 years of operation," he added.

Flight tracking website Flightradar24 said 1,300 flights were canceled to and from U.K. airports on Tuesday, and that 177 flights had been canceled as of early Wednesday morning.

Nearly all the cancelations were at London's Heathrow, one of Europe's busiest airports. London's Stansted and Gatwick airports, Birmingham and Manchester were also severely impacted.

The technical issue was confirmed by National Air Traffic Services (NATS) shortly before 2 p.m. local time on Tuesday. While it was resolved by 7:30 p.m., severe travel disruption continued into Wednesday due to a backlog of flights, aircraft and crews being in the wrong place, and staff reaching the end of shift limits. Passengers due to fly Wednesday have been urged to check with their airline for updates.

Rolfe said NATS took responsibility for the impact on passengers, airlines and airports.

"We never do this lightly, we only do it when there is an issue that cannot be solved quickly and we have to take action to make sure that those who are flying, who are in the air at the time, are safe," he told the BBC.

"When we can restore these incredibly complex systems, we do so as quickly as we possibly can."

NATS runs air traffic control services for 15 U.K. airports, handling around 2.5 million flights a year, and is responsible for managing the U.K.'s upper airspace used by commercial jets.

Airlines directed sharp criticism at the organization and its leadership on Wednesday, noting that the latest incident followed two other major failures in recent years.

A radar technical issue in July 2025 led to more than 150 cancellations, while widespread travel chaos lasted for days over a long weekend in August 2023 due to problems with NATS' flight plan processing sub-system.

Neal McMahon, chief operating officer of Ireland's Ryanair, called it an "abhorrent" failure by NATS that had hit families traveling on holiday and people traveling for work.

"The astonishing part is that NATS continues to charge airlines and passengers more each year while delivering a worse service. Following the 2023 collapse, we were told lessons would be learned... Yet here we are again," McMahon said in a statement.

A spokesperson for low-cost carrier Wizz Air told CNBC the airline was "extremely disappointed that another NATS technical failure has caused widespread disruption across the U.K. aviation network."

"Passengers are once again facing delays and cancellations because of a failure entirely outside airlines' control," they said.

Passengers flying from Heathrow have been hit by further disruption recently.

Rail links to Britain's busiest airport were suspended at the weekend due to a fire, while the entire airport shut down for almost a whole day in March 2025 due to a power outage at a nearby electrical substation.