Airlines are demanding answers after thousands of passengers travelling to and from UK airports were left facing severe delays when a technical issue affecting radar systems closed airspace on Wednesday.
Airports including Heathrow and Gatwick were affected by the outage, with travel hubs as far north as Edinburgh reporting that flights had been grounded shortly after 4pm UK time.
Eurocontrol, the EU-wide air traffic control agency, reported that the London control area was “temporarily unavailable due to technical issues”.
As thousands of travellers faced cancellations, an update by NATS – a national air traffic control agency – provided more positive news, with the organisation stating that air traffic control systems are now “fully operational” shortly after 5pm.
"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," they explained.
Despite fully functioning radar systems, all airports have warned that travellers are set to face severe delays exceeding three hours to UK-bound airports.
Latest reports show that 84 outbound flights have been cancelled so far across all UK airports and 71 arrivals have been cancelled.
Passengers are encouraged to check with their airport before travelling, with ongoing delays and cancellations expected.
There were calls today – made by Ryanair’s chief operating officer – for the head of the UK’s air traffic control company Martin Rolfe to resign in the wake of yet another ATC disaster.
A similar outage in August 2023 left more than 700,000 passengers affected by the cancellation of more than 500 flights at the UK's busiest airports.
The chaos – when Rolfe was at the helm – took several hours to resolve because an engineer was working from home.
Ryanair’s chief operating officer Neal McMahon said: “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 Aug 2023 Nats system outage, and passengers continue to suffer as a result of Martin Rolfe’s incompetence.”
A spokesperson for NATS said the potential cause of the air traffic disruption was a radar-related issue. This was resolved by quickly switching to the back-up system.
The spokesperson added that during this time, they reduced traffic to ensure safety.
There is no evidence that the technical issue was cyber related, they added.
It comes as one passenger, stranded aboard a London-bound flight at Italy's Treviso airport in Venice, told LBC the captain had told passengers: "traffic control over London is blocked".
Maps emerging online show the aftermath of the outage, with a cluster of aircraft gathered at London airports, leaving airspace across the south of England largely clear of air traffic.
ℹ️Technical issue at Swanwick
As a result of a technical issue at NATS Swanwick air traffic control centre, we are limiting the number of aircraft flying in the London control area in order to ensure safety, which is always our first priority.
(1/3) pic.twitter.com/HzBYPGcq7M— NATS (@NATS) July 30, 2025
Transport Secretary Heidi Alexander has said “continued disruption is expected” after the Nats radar failure this afternoon.
“I am aware of a technical issue which impacted Nats’ operations causing travel disruption this afternoon,” the Cabinet minister posted on X.
“I have been informed systems have now been restored but continued disruption is expected, and passengers should check with individual airports for advice.”
Passengers have also taken to social media to show pictures of themselves stranded on runways across the London area.
A source at Eurocontrol said the radar failure was an isolated incident affecting the UK, with no reported outages across continental Europe.
British Airways said the number of flights departing from and landing at Heathrow is restricted to 32 per hour.
Its flight traffic will resume to the normal level of 45 per hour at 19:15.
London City airport has warned that some flights may now be cancelled, posting a statement to X that read: “Due to a technical issue with air traffic control across the London area, flights in and out of London airports – including London City Airport – might be delayed or subject to cancellation.”
I am aware of a technical issue which impacted @NATS operations causing travel disruption this afternoon.
I have been informed systems have now been restored but continued disruption is expected, and passengers should check with individual airports for advice.— Heidi Alexander MP (@Heidi_Labour) July 30, 2025
In a statement, Sir Ed Davey, the Lib Dem leader, said: “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.
“With thousands of families preparing to go on a well-earned break, this just isn’t good enough.
“The Government should launch an urgent investigation to ensure the system is fit for purpose, including ruling out hostile action as a cause.
“The public deserve to have full confidence in such a vital piece of national infrastructure.”
As news of the outage broke, a London Gatwick spokesperson said: "A technical issue impacting NATS that affected outbound flights across the UK has now been resolved. As a result there are some delays at London Gatwick while operations resume.
"Passengers should check the status of their flights with their airline."
One passenger told LBC the pilot had warned that "a queue of flights" would be waiting to land when planes are eventually able to re-enter airspace.
In a statement, a London Gatwick spokesperson said: "A technical issue impacting NATS is affecting all outbound flights across the UK.
"There are currently no departures from London Gatwick while the situation is being resolved."
This was updated less than an hour later, as aircraft resumed arrivals and departures to major London airports.
⚠️ UK ATC Radar Failure 📡
Due to a Technical fault with Radars in the London CTA, many aircraft are facing delays.
London CTA (London Airspace) is UNAVAILABLE until further notice
Update to follow
📸 Eurocontrol#aviation #avgeek #Dublin #Ireland #Travel #planes #UK #ATC… pic.twitter.com/s6NxpXHja5— Shauns_Aviation🇮🇪✈️ (@Shauns_Aviation) July 30, 2025
Following the outage, airlines are demanding answers regarding the steps being taken by Nats to stop issues from happening again.
EasyJet’s chief operating officer David Morgan said: "It’s extremely disappointing to see an ATC failure once again causing disruption to our customers at this busy and important time of year for travel.
"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."
