The UK’s air traffic control service, NATS, is facing intense scrutiny following a second serious system failure in two years that caused widespread flight disruptions across the country and upended summer travel plans for thousands of passengers.
On Wednesday afternoon, flights were grounded nationwide after a “technical issue” emerged at NATS’ air traffic control centre in Swanwick. The outage halted flight departures and briefly cleared London’s normally congested skies. Though the fault was resolved by 4:25pm and systems fully restored by 5:00pm, the disruption had already triggered severe delays at the UK’s busiest airports, including Heathrow, Gatwick, Manchester, and Edinburgh.
NATS issued an apology and confirmed that airport departures had resumed, adding that it was working with airlines to safely manage the backlog of flights. Despite these reassurances, the failure sparked widespread calls for accountability and raised questions about the agency’s preparedness.
Ryanair’s Chief Operating Officer, Neal McMahon, condemned the disruption as “outrageous” and criticized NATS CEO Martin Rolfe for failing to prevent a recurrence of the 2023 incident, which had lasted longer and affected over 700,000 passengers. McMahon urged Transport Secretary Heidi Alexander to dismiss Rolfe if he did not resign voluntarily.
Liberal Democrat leader Sir Ed Davey also called for an urgent investigation into the outage, stating: “It is utterly unacceptable that after a major disruption just two years ago, air traffic control has once again been hit by a technical fault.” He emphasized the impact on thousands of families relying on the summer holidays for much-needed respite.
Aviation analytics firm Cirium reported 45 flight cancellations and 35 cancelled arrivals by early Wednesday evening, with many more delays expected. British Airways, Heathrow’s largest airline, apologized for the inconvenience and said teams were working to resume normal operations.
The Civil Aviation Authority (CAA) previously estimated the 2023 outage had cost airlines and consumers up to £100 million. A subsequent investigation produced 30 recommendations aimed at preventing future failures and improving response to large-scale disruptions. However, critics argue that these measures have proven insufficient.
NATS, which is 51% owned by a consortium of airlines and airports—with the government holding a 49% stake and a controlling “golden share”—has not disclosed the exact nature of the fault. A government official said there was no indication of malicious interference.
Transport Secretary Heidi Alexander acknowledged the issue on social media, confirming that systems were back online but warning of continued delays. She advised passengers to consult their respective airports for the latest updates.
This latest setback follows a separate crisis in March, when a fire at a nearby electrical substation caused a near-total shutdown of Heathrow for 24 hours due to a power outage.
As pressure mounts on NATS and government officials, the incident raises serious concerns about the resilience of the UK’s air traffic infrastructure and its capacity to safeguard critical travel periods.
