LONDON — Flights departing from Heathrow, Gatwick and several other major British airports were grounded Tuesday afternoon after a technical failure struck the United Kingdom’s air traffic control provider, National Air Traffic Services, causing widespread disruption across the country’s aviation network.

NATS confirmed the technical problem originated at its Swanwick air traffic control center on England’s south coast, with departures at Heathrow halted entirely from approximately 12:48 p.m. local time.

“We have a technical problem at NATS Swanwick air traffic control centre which is causing some disruption to flight departures,” a NATS spokesperson said. “Our engineers are on site and we will provide an update as soon as we can.”

Heathrow, the United Kingdom’s busiest airport, confirmed the disruption in its own statement, emphasizing that engineers were actively working to resolve the issue.

“We are investigating a technical issue which is causing some disruption to flight departures,” Heathrow said in a statement, adding that it was “supporting our local NATS team in their efforts to resolve the issue as quickly as possible.” The airport said arriving flights were not currently affected by the disruption, though it advised passengers to check their specific flight times given the broader disruption unfolding across the network.

Gatwick Airport confirmed it was similarly affected, issuing its own statement acknowledging the scope of the problem.

“We are aware of a NATS technical issue that is currently affecting a number of UK airports, including London Gatwick,” Gatwick said, advising passengers to check directly with their airlines for updated flight information.

Beyond Heathrow and Gatwick, flight tracking service Flightradar24 reported that arrivals and departures were being heavily regulated at airports across London’s broader airspace region, known as the London EGTT Flight Information Region, due to the air traffic control equipment issues. According to reporting from ITV News, additional affected airports included Southend, the Isle of Man and Jersey, while Edinburgh Airport separately confirmed in a statement on social media that the NATS issue could impact its own operations as well.

“We are aware of a technical issue affecting NATS which may impact operations,” Edinburgh Airport said. “We are working closely with air traffic control, airlines and other partners, and hope NATS can resolve the issue as quickly as possible.”

According to LBC’s reporting on the disruption, additional UK airports affected by the delays included Aberdeen, Manchester, East Midlands Airport, Birmingham, Bristol and London Stansted, alongside London City Airport, illustrating the broad geographic scope of Tuesday’s technical failure across the country’s air traffic network.

Passengers affected by the disruption took to social media to describe their experiences waiting on grounded aircraft, with some reporting being held on the tarmac for extended periods following the fault. One passenger described being stuck on the tarmac at Heathrow for 90 minutes after landing from Seattle, while another described a British Airways flight returning to a stationary position with its engines off while awaiting further updates.

Flightradar24 cited data from Eurocontrol, Europe’s air traffic coordination body, indicating an expected return to normal traffic flow around 8 p.m. UTC, though the exact timeline for full resolution remained uncertain as engineers continued working to address the underlying technical issue at the Swanwick facility.

Tuesday’s disruption comes amid what industry data has described as record or near-record traffic levels across many European airports throughout the summer travel season. Heathrow specifically has ranked among the continent’s busiest hubs in 2026, handling more than 1,200 daily flights at points earlier in the year, placing persistent pressure on runway and airspace capacity even before Tuesday’s technical fault. With 84.5 million passengers passing through the airport last year, Heathrow ranked seventh among the world’s busiest airports globally, according to data published by Airports Council International.

Industry analysts have noted that the timing of Tuesday’s fault landed at a particularly sensitive moment for the aviation network, given that late-summer traffic remained elevated and many airlines were already operating close to the limits of their available fleet and crew capacity. That tight scheduling environment has raised concerns that aircraft and flight crews could end up out of position even after the immediate technical issue at NATS is resolved, potentially compounding disruption for affected flights well beyond the initial hours of the outage.

Tuesday’s incident is not the first time NATS has faced scrutiny over technical reliability in recent years. A software-related failure in August 2023 severely limited the number of flight plans the system could process, resulting in more than 2,000 flight cancellations over two days and affecting roughly 700,000 passengers, according to figures previously cited by U.K. transport officials. That earlier incident prompted the U.K.’s Transport Secretary at the time to summon NATS leadership for direct questioning over the reliability of the country’s air traffic management systems, with officials later attributing the disruption to a radar-related issue that had been resolved by switching to a backup system.

Travel rights organizations and consumer advocacy groups have continued to urge passengers experiencing disruption during major incidents like Tuesday’s fault to rely primarily on official airline updates and verified departure and arrival board information, rather than unconfirmed claims circulating on social media, given how quickly and unpredictably disruption of this kind can evolve across a national air traffic network.

As of Tuesday afternoon, NATS had not provided a detailed public explanation of the specific technical cause behind the Swanwick center failure, though the organization confirmed engineers remained on site actively working to restore normal operations. Passengers with flights scheduled to depart from Heathrow, Gatwick or the other affected UK airports were advised to check directly with their individual airlines for the most current information regarding delays, cancellations or gate changes as engineers continued working to resolve the underlying air traffic control system issue.