LONDON — A technical glitch which has caused hundreds of U.K. flights to be disrupted could take “days” to fix, causing chaos for passengers during the busy summer travel period.
Hundreds of flights were delayed and canceled Monday after a systems failure at the U.K.’s air traffic control services left operators unable to automatically process flight plans.
Britain’s National Air Traffic Service said several hours later that it had resolved the issue, but warned that it would take time for normal flight schedules to resume.
“It will take some time for flights to return to normal, and we will continue to work with the airlines and the airports to recover the situation,” NATS Operations Director Juliet Kennedy said in a statement.
Kennedy added that the cause of the issue is currently being investigated.
More than a quarter (27%) of all flights traveling to and from U.K. airports were canceled on Monday, according to data from aviation analytics firm Cirium.
In total, 790 departures and 785 arrivals were canceled, with London’s busiest airport, Heathrow, facing the greatest disruption, followed by London Gatwick and Manchester.
Britain’s transport secretary, Mark Harper, said Tuesday that the disruption would take “some days” to resolve.
“I accept it’s disrupted thousands of people and it is going to take some days to get people back to where they should be,” Harper told BBC Radio 4’s “Today” show.
The issue comes during the U.K.’s busy public holiday travel period, with many people returning from summer vacations.
The U.K.’s Civil Aviation Authority is investigating the cause of the failure, Harper said, adding that the government was “clear it wasn’t a cyberattack.”