London, UK – Heathrow Airport, Europe's busiest air hub, experienced significant disruption yesterday, Wednesday, July 30, 2025, and continues to face a backlog of cancellations and delays today, Thursday, July 31, 2025, following a major technical issue within the UK's National Air Traffic Services (NATS). The widespread system failure, attributed to a radar fault at the NATS Swanwick control center, led to the grounding of departing flights across the UK and left thousands of passengers stranded.
The technical glitch, which occurred yesterday afternoon, forced NATS to limit the number of aircraft flying in the London control area to ensure safety. While the issue was reportedly resolved within 20 minutes by switching to a backup system, the ripple effect on flight schedules has been profound. Aviation analysts Cirium reported over 150 flights cancelled across UK airports on Wednesday, with Heathrow bearing the brunt of the disruption, seeing 29 departures and 17 arrivals scrapped.
Passengers at Heathrow and other affected airports, including Gatwick and Edinburgh, reported scenes of chaos, long queues, and poor communication from airlines. Many travellers found their plans severely impacted, with flights diverted, some returning to their departure cities, and others facing lengthy delays. The incident has left passengers frustrated, missing important commitments such as weddings and business appointments.
This latest incident has reignited concerns about the resilience of the UK's air traffic control infrastructure, especially given a similar outage in August 2023 that also caused widespread disruption. Transport Secretary Heidi Alexander confirmed that the systems have now been restored but warned of continued disruption as airports and airlines work to clear the backlog. She urged passengers to check with their individual airlines for the latest information.
Airlines, including British Airways, were forced to restrict their flight rates at Heathrow for several hours, contributing to the substantial number of cancellations. While NATS has confirmed there is no evidence of a cyber-related cause for the radar failure, calls for comprehensive investigations and improved investment in air traffic management infrastructure are mounting from industry experts and frustrated passengers alike.
As Heathrow and other UK airports gradually return to normal operations, the focus remains on minimizing ongoing disruption and addressing the underlying issues to prevent similar occurrences in the future. Passengers planning to fly from Heathrow in the coming days are advised to anticipate potential lingering delays and to verify their flight status before travelling to the airport.