U.K. Airports Hit by Flight Delays Over ‘Technical Issue’

Britain’s air traffic control service experienced a “technical issue” on Monday, significantly disrupting hundreds of flights in and out of the country.

The problem “is affecting our ability to automatically process flight plans,” the National Air Traffic Service said in a statement, adding that flight plans were now being entered manually, “which means we cannot process them at the same volume.”

While British airspace was not closed, the agency said, it had restricted the number of flights departing from airports in order to maintain safety while it tried to fix the problem.

The delays are hitting at a heavy travel period, as people return from vacations or extended trips on Monday’s “bank holiday,” or national day off, in Britain. Customers were advised to check the status of their flight before traveling to airports.

As the flight restrictions continued into the afternoon, thousands of travelers were stuck in airports or on runway tarmac, facing long delays or uncertain departure times.

In Palma de Mallorca, Jon Hughes, 49, boarded a plane bound for the English city of Leeds at about 1 p.m. local time with his two children, ages 13 and 15. On board, he said, they were told that the plane had been allotted a departure slot in about seven hours.

“It’s very hot and kids are getting restless,” he said in a message. “We don’t know how long we will be stuck on the plane. Or even if we will get home today.”

On Monday, 3,049 flights were scheduled to leave British airports and 3,054 to arrive, according to Cirium, the aviation analytics company.

The European air control agency, Eurocontrol, reported that Britain was experiencing “a flight data processing system failure” with “very high individual delays.”

“Currently there is no indication of when a solution for the failure will be available so no improvements for flights entering U.K. airspace are foreseen in the near future,” it added

The low-cost airline Ryanair said that it would be forced to delay and cancel flights to and from Britain on Monday. Passengers would be able to change flights or receive a full refund, it said in a statement.

Jamie Steele, 39, a British nurse returning to Manchester from a vacation in the Italian city of Pisa, was set to depart at 10.30 a.m. local time. Four hours later, he was still sitting in the plane on the tarmac. The pilot told them they would have a slot in the next three hours, but added that he was “not sure he trusts the time given.”

“It’s difficult not knowing the time we will get home,” Mr. Steele said in a message.

Heathrow Airport, near London, advised passengers to contact their airline before heading there, and Edinburgh Airport told passengers not to come to the site before checking the status of their flight.

Louise Haigh, the lawmaker in charge of transport policy for the opposition Labour Party, described the disruption on social media as “extremely concerning for passengers” on “one of the busiest days of the year.” She added that she was surprised the government’s minister for transport had yet to make a statement.

The Scottish airline Loganair warned on social media that there had been “a network-wide failure of U.K. air traffic control computer systems this morning.”

The number of flight departures during the three days of holiday weekend was scheduled to be 10 percent higher than the same period the year before, according to Cirium, and 83 percent higher than in 2021, when the Covid-19 pandemic drastically reduced air travel.

European flights were disrupted for hours in December 2014 because of a technical problem at an air traffic control center in Swanwick, England.