LONDON – The British air traffic control system said on Monday that it was affected by a technical problem that threatened delays and cancellations of flights in and out of the country on a busy national holiday.
“We are currently experiencing a technical issue and have implemented traffic flow restrictions to ensure safety,” a spokesman for Britain’s National Air Traffic Service told NBC News just after 12:30 p.m. local time (7:30 a.m. ET).
It said engineers were working to find and fix the fault, but it wasn’t clear how long it would take to fix the problem.
London’s largest international hub, Heathrow Airport, said it was “disrupting flights across the UK due to national airspace issues.”
Stansted and Gatwick airports in London and Manchester Airport in northern England said flights were affected by the problem.
The European air traffic control authority Eurocontrol warned of “very long” delays due to a “failure of the flight data processing system” in the United Kingdom
The Scottish airline Loganair previously announced in a statement post on X, the social media platform formerly known as Twitter, that there had been a “network-wide outage of UK air traffic control computer systems” early Monday.
The airline said it was confident it could operate most flights within Scotland with minimal disruption but said there could be delays to north-south and international flights due to the problem.
The incident occurred on a busy travel day for UK residents as Monday is a national bank holiday.
Several social media users said they were stuck on planes on the tarmac. NBC News was not immediately able to verify their accounts.
A traveler who told Reuters they were on a plane that was stuck on the tarmac in Budapest said the pilot informed passengers they were delayed due to a massive computer failure.
They said passengers may face a delay of 8 to 12 hours. NBC News could not immediately verify this.
This is an evolving story. Please check again for updates.
The Associated Press and Reuters contributed.