Britain’s National Air Traffic Service (NATS) said in a Monday afternoon statement that it had “identified and remedied” an IT issue that affected automated flight planning throughout the country, including at London’s Heathrow, one of the busiest international airports in the world.
NATS said it never closed down U.K. airspace, but applied “traffic flow restrictions” while air traffic controllers had to revert to manual systems to sequence plane departures and landings.
“We are now working closely with airlines and airports to manage the flights affected as efficiently as possible. Our engineers will be carefully monitoring the system’s performance as we return to normal operations,” NATS said.
About 3,000 flights were due to arrive in the country on Monday, and another 3,000 had been scheduled to depart.
“Any glitch that impacts approximately 1 million passengers is a serious issue” said Paul Charles, an aviation expert. “These systems should not be falling over, especially on one of the busiest days of the year.”
“It’s a symbol of our wider IT infrastructure, creaking at the seams,” he said, suggesting that there had been a lack of investment during the coronavirus pandemic, when travel slowed.
The impact on Monday went far beyond Britain. The European air control agency, Eurocontrol, warned of “very high” delays because Britain was experiencing “a flight data processing system failure.” Ireland’s air traffic controller, AirNav Ireland, said in a statement that there were “significant delays for flights across Europe that are traveling to, from or through UK airspace.”
Passengers caught up in the chaos shared their experiences.
The Washington Post’s Jennifer Hassan on Monday morning boarded an easyJet flight in Inverness, Scotland, destined for London’s Luton airport. But after nearly two hours on the tarmac, passengers were asked to disembark the plane and told to expect a six-to-seven hour delay.
Sky News producer Georgia Ziebart said her flight — from Palma, Majorca to London’s Gatwick Airport — was told that all planes in the air when the system went down had been diverted to other countries.