The UK's National Air Traffic Services (NATS) on Wednesday ruled out a cyberattack having caused the massive disruption across airports in the country, which also impacted several flights to and from India.
Tens of thousands of passengers were affected by the disruption on Tuesday, which led to around 2,000 flights cancelled and the knock-on effects spilling over for a second day.
Heathrow, the UK's busiest hub airport, led the cancellations and delays tally alongside Gatwick, Stansted, Luton and Manchester.
Deep Dive
What caused the recent disruptions in UK airports?
Why did NATS rule out a cyberattack in the airport disruptions?
How is NATS addressing the backlog of delayed and cancelled flights?
Also Read | Over 600 flights cancelled as London's Heathrow, Manchester among UK airports hit by technical issue
"We will be doing a very thorough and full investigation. We have at this point ruled out a cyberattack," NATS CEO Martin Rolfe told the BBC.
"I don't believe we have ever seen an incident happen more than once. This will be something we haven't seen in more than 50 years of operation. I would say the UK has one of the best reputations in the world, both from a safety perspective and resilience perspective," he said.
NATS has claimed that the problem occurred in its flight processing system, reiterating that it was not the same fault as those that caused outages and mass disruption in 2023 and 2025.
{{/usCountry}}NATS has claimed that the problem occurred in its flight processing system, reiterating that it was not the same fault as those that caused outages and mass disruption in 2023 and 2025.
{{/usCountry}}UK Transport Secretary Heidi Alexander has called the CEO in for a briefing amid calls for his resignation after the third major air traffic collapse under his watch. The UK government holds a 49 per cent stake in the air traffic controller.
Also Read | ‘Absolute nightmare’: 65,000+ passengers hit as over 1,000 flights cancelled across the UK
Heathrow Airport issued a statement on Wednesday saying that while flights are now operating, disruption would continue as airlines "reposition aircraft and crew".
"We apologise to those affected and have extra colleagues across our terminals to support passengers while we work with NATS and airline partners to restore normal operations as quickly as possible," it stated.
Air India is among the airlines impacted following the technical fault at NATS, being forced to "divert, delay or cancel multiple flights scheduled to operate to and from UK airports".
"This may lead to delays in some of our other services, too, as our aircraft and crews are out of position following the disruption... We are closely monitoring the situation and are making every effort to minimise disruptions as much as possible," it stated.
Also Read | Air traffic control issue disrupts flights at major UK airports
While Hungarian budget airline Wizz Air said NATS was "not fit for purpose", Ryanair has demanded its CEO's resignation.
In 2023, NATS' main flight plan processing system completely failed, forcing the total closure of British airspace to all incoming flights. The failure cost airlines 65 million pounds in diversion costs and passenger compensation claims, and disrupted 700,000 people's journeys, an official report later found.
In July last year, a NATS radar system failed, leaving controllers blind as to aeroplanes' whereabouts.