 "UK airport chaos: What led to over 100 flights being cancelled across Britain?")
The United Kingdom’s skies came to a halt on Wednesday when a major technical problem struck the nation’s air traffic control system, forcing the grounding of flights and triggering chaos at the peak of the summer holiday season.
While the fault has now been fixed, the aftermath is stretching into days, with stranded passengers, diverted aircraft and mounting anger across the aviation sector.
What caused the travel chaos
The trouble began on Wednesday afternoon when radar screens at the National Air Traffic Services (NATS) Swanwick control centre in Hampshire abruptly stopped displaying flight data.
This control hub manages a large portion of the UK’s airspace, particularly flights operating above 24,500 feet.
When the glitch occurred, controllers were unable to accept new aircraft into British skies, and planes already on the ground at airports across the country were stopped from taking off.
NATS confirmed that the fault was “radar-related” and said that engineers switched to a backup system to keep operations safe, albeit at a slower pace.
A spokesperson explained to Reuters that the issue “was resolved by quickly switching to the back up system during which time we reduced traffic to ensure safety.”
The organisation later reassured travellers, “Our systems are fully operational and air traffic capacity is returning to normal… Departures at all airports have resumed and we are working with affected airlines and airports to clear the backlog safely. We apologise to everyone affected by this issue.”
Although NATS announced the outage lasted only around 20 minutes before a workaround was found, the knock-on effects were far more severe.
Flights were held on the ground, aircraft already airborne were diverted, and crews and planes ended up out of position, causing a ripple of cancellations and delays that extended into the evening and are expected to continue for days.
Which airports were affected
The disruption hit almost every corner of the UK aviation network. Heathrow Airport, the country’s largest and Europe’s busiest hub, saw arrivals and departures significantly reduced.
British Airways, Heathrow’s largest operator, had to limit flight movements to just 32 an hour for much of Wednesday afternoon – a sharp reduction from its normal 45.
Gatwick, Birmingham, Manchester, Edinburgh, London City, and even regional airports such as Cardiff all reported delays.
London City Airport saw some of the most dramatic disruptions, including a British Airways flight from Glasgow that was forced to abandon its route and return to its departure point.
Passengers waiting for flights to a host of destinations – from Berlin to Marseille and from Glasgow to Frankfurt – were left sitting on planes or stranded in terminals.
Aircraft heading for the UK that were already in the sky were ordered into holding patterns or diverted to other European airports, with some landing in Amsterdam, Paris, or Brussels instead.
Flight tracking data showed more than 80 cancellations by 5:30 pm, according to aviation analytics firm Cirium, with many more delays.
Ryanair, one of the airlines most vocal about the disruption, said delays and diversions lasted “over four hours” and caused “inconveniencing thousands of passengers.”
Which airlines were affected the most
The disruption was not confined to one airline – almost every carrier operating in UK airspace was affected – but British Airways bore the heaviest burden because of its dense Heathrow schedule.
The airline saw virtually all of its Wednesday evening flights delayed, with some transatlantic services to cities like Chicago, New York JFK and Pittsburgh departing more than two hours late.
Flights to European destinations such as Prague, Valencia, and Nice were similarly affected.
British Airways admitted the issue was impacting operations, saying the problem was “affecting the vast majority of our flights,” and worked to reroute or reschedule where possible.
Heathrow even considered relaxing its overnight noise curfew to allow late flights in an attempt to catch up with the mounting backlog.
EasyJet also suffered substantial disruption, cancelling at least 16 flights out of Gatwick.
Its Chief Operating Officer David Morgan issued a pointed statement, saying: “While our priority today is supporting our customers, we will want to understand from NATS what steps they are taking to ensure issues don’t continue.”
Low-cost carrier Ryanair, which operates across multiple UK airports, condemned the disruption more bluntly. Calling the incident “utterly unacceptable,” the airline demanded accountability from the air traffic control provider.
NATS faces growing backlash
This is not the first time Britain’s air traffic control system has faltered. A serious failure in August 2023 caused havoc for at least 700,000 passengers, disrupting thousands of flights and leaving airlines and passengers facing costs estimated at over £100 million.
The recurrence of another system failure within two years has led to growing frustration from airlines and calls for leadership changes at NATS.
Ryanair’s Chief Operating Officer Neal McMahon accused NATS management of failing to prevent a repeat of 2023’s disruption, stating, “It is clear that no lessons have been learnt since the Aug ‘23 NATS system outage and passengers continue to suffer as a result of Martin Rolfe’s incompetence.”
The airline also directly called for NATS Chief Executive Martin Rolfe to step down.
McMahon went further, saying: “It is outrageous that passengers are once again being hit with delays and disruption due to Martin Rolfe’s continued mismanagement of NATS. Yet another ATC system failure has resulted in the closure of UK airspace meaning thousands of passengers’ travel plans have been disrupted. It is clear that no lessons have been learnt since the August 2023 NATS system outage and passengers continue to suffer as a result.”
EasyJet, while more measured, also signalled it expects answers. “While our priority today is supporting our customers, we will want to understand from NATS what steps they are taking to ensure issues don’t continue,” said Morgan.
What London has said
The UK’s Transport Secretary Heidi Alexander acknowledged the situation, warning that “continued disruption is expected” and advising passengers to “check with individual airports for advice.”
The Liberal Democrat leader Sir Ed Davey criticised the repeated failures, calling for a government-led investigation. “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,” Davey said.
“The Government should launch an urgent investigation to ensure the system is fit for purpose, including ruling out hostile action as a cause.”
The UK Department for Transport echoed the call for answers but pointed out that the immediate crisis had passed.
A spokesperson said: “While passengers should continue to check with individual airports for advice, NATS have confirmed their systems are now fully operational and flights are returning to normal. We are working closely with NATS to understand the cause of the technical issue and the implications for the resilience systems in place.”
NATS has not ruled out the possibility of cyber interference or hostile foreign action, though it has provided no evidence of such a link.
The company has so far declined to comment on Martin Rolfe’s position or further details on the root cause, saying only that “our engineers have now restored the system that was affected this afternoon. We are in the process of resuming normal operations in the London area. We continue to work closely with airline and airport customers to minimise disruption. We apologise for any inconvenience this has caused.”
Why the impact will last for days
Despite the relatively short duration of the fault – around 20 minutes before NATS switched to backup systems – the fallout is immense because of how tightly airline schedules run, especially in summer.
Aircraft and crews were scattered across unintended destinations. Some flights were cancelled outright because aircraft were out of position, while others had to turn back mid-route, creating a cascading effect that will take time to untangle.
Holidaymakers hoping for quick recovery may be disappointed. Airlines are already under pressure during the peak travel season, and every delay or diversion causes additional scheduling complications.
Adding to passenger frustration, most travellers will not be entitled to financial compensation.
Because the air traffic control failure was outside of airline control, carriers are not obligated to pay out under EU and UK compensation rules, though they must provide support like rebooking or hotel accommodation if needed.
By Wednesday evening, NATS announced that “departures at all airports have resumed” and that its systems were “fully operational.”
Heathrow, Gatwick and Edinburgh airports confirmed operations were restarting, but the backlog of stranded aircraft and displaced crews means many schedules remain in disarray.
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