Air traffic across the United Kingdom faced severe disruption on Wednesday after a technical glitch hit the National Air Traffic Service (NATS), leading to widespread flight delays and diversions. The fault occurred at NATS’ control center in Swanwick, southwest of London, significantly reducing the number of planes able to take off—around 13 aircraft were grounded every hour during the outage.

The impact was felt most heavily at Heathrow Airport, where a high volume of departures was halted. Gatwick Airport confirmed that incoming flights were also affected, with several either paused or rerouted due to safety concerns. Though engineers managed to resolve the issue within about 20 minutes, it took additional time to fully restore normal operations across the airspace.

This isn’t the first time NATS has encountered technical trouble. The system, which has been in use since 2002, has experienced several glitches over the years. Notably, in August 2023, a major failure forced air traffic controllers to switch to manual flight planning, resulting in the delay or cancellation of hundreds of flights during peak holiday season and impacting nearly 700,000 passengers.

While flight operations have now largely resumed, Transport Secretary officials have warned of continuing delays and residual disruptions. The incident has reignited criticism of NATS' infrastructure reliability, with growing public pressure for the resignation of the agency's top leadership.