Air traffic outage live: Radar systems failure caused shutdown as flight delay chaos could continue for days

What caused the air traffic outage?

The latest failure at Nats, the main air traffic control provider, led to dozens of diversions and cancellations – particularly affecting London Heathrow and Gatwick airports.

British Airways has cancelled a number of flights this morning to Heathrow, while easyJet says it has been rebooking disrupted passengers on alternative flights after multiple cancellations. Ryanair has once again called for the resignation of the Nats chief executive.

Read the full explainer from our travel correspondent Simon Calder here:

Holly Evans31 July 2025 11:54

Air traffic disruption caused by 'radar-related issue'

A "radar-related issue" caused the air traffic control (ATC) failure that grounded flights across the UK on Wednesday, officials have said.

It comes as airlines demand an explanation for what happened, with Nats chief executive holding a meeting with transport secretary Heidi Alexander.

A spokesperson for Nats said: "This was a radar-related issue which was resolved by quickly switching to the back-up system during which time we reduced traffic to ensure safety.

"There is no evidence that this was cyber related."

Holly Evans31 July 2025 11:38

Transport secretary urges passengers to check with airlines

Despite flights resuming, the transport secretary has urged passengers to check with their airlines before making their journeys as the knock-on effect continues from Wednesday’s air traffic systems failure.

Heidi Alexander said: “I know that any disruption is frustrating for passengers.

“Flights are now resumed and I am grateful to airlines who are working hard to get people to where they need to be. I will continue to receive regular updates.

“Passengers should check with airlines before travelling.”

Holly Evans31 July 2025 11:23

Disruption was an 'isolated event' with no sign of 'malign activity'

The disruption across the National Air Traffic Service (Nats) which saw 150 flights grounded was an “isolated event”, the transport secretary has said.

In a post on social media, Heid Alexander said: “I have spoken with @NATS CEO Martin Rolfe who provided further detail on yesterday’s technical fault. This was an isolated event and there is no evidence of malign activity.”

Holly Evans31 July 2025 11:10

Full story: Air control boss hauled in for grilling from transport secretary amid calls for him to resign after airports chaos

Passengers across Europe were stranded during the peak holiday season when planes were cancelled and diverted – with some turning around mid-air to return to their departure cities – because of a 20 minute glitch.

Political correspondent Archie Mitchell has the full story:

Tara Cobham31 July 2025 10:45

Software 'system glitch caused shutdown', according to reports

A “software glitch” with the radar systems was the cause of the air traffic control systems failure on Wednesday, according to reports.

Sources told The Times that air traffic controllers were left with a patchy picture of the airspace after software that is supposed to relay information to their screens broke down.

The newspaper reported that restrictions were “immediately” put in place by bosses at Nats, which is in charge of UK airspace, as they prioritised safety.

Within 20 minutes of the initial collapse, a back-up system was reportedly put online and continues to be used as investigations into the shutdown continue.

A source told The Times: “This was a genuine software error and the back-up systems worked as they should. They run a different programme so there is no chance of the same issue happening twice.”

The Independent has approached Nats for comment.

Tara Cobham31 July 2025 10:28

UK suffers more flight cancellations after air traffic failure

Nearly two dozen flights to and from UK airports were cancelled on Thursday, a day after technical problems with Britain's air traffic control system caused widespread disruption across the country.

National Air Traffic Services (NATS), which provides air traffic control services for planes flying in UK airspace and the eastern part of the North Atlantic, said on Wednesday its systems were fully operational with capacity returning to normal after it switched to a back-up system.

The second outage in recent years at NATS also affected Gatwick Airport near London, Edinburgh Airport in Scotland, and other locations, resulting in 122 cancellations as of 6.30pm GMT on Wednesday, according to aviation analytics firm Cirium.

NATS is working closely with airlines and airports to clear the backlog, Alexander wrote on social media platform X. Across UK airports, 12 departures and 11 arrivals had been cancelled on Thursday as of 7.30am GMT, according to Cirium.

At least 16 flights, including departures to Brussels and Toronto and arrivals from New York and Berlin, had been cancelled at Heathrow Airport, according to its website.

Tara Cobham31 July 2025 10:15

Explained: What rights do you have to compensation for cancelled flights?

Travellers may be entitled to care while they wait – but not, as this was beyond the control of airlines, compensation. But your rights depend on where your flight begins and the airline involved.

For all flights from the UK and EU airports (as well as those in the wider EEA), European air passengers’ rights rules prevail. These were introduced in 2006 and are known as EC261. After Brexit, the UK copied and pasted the same regulations into British law as UK261.

The Independent’s travel correspondent Simon Calder explains:

Tara Cobham31 July 2025 10:00

Delays stretch to 20 hours for some passengers

The Independent’s travel correspondent Simon Calder reports:

The knock-on effects of the air-traffic control failure on Wednesday are continuing. EasyJet passengers from Chania in Crete to London Gatwick whose flight was diverted to Zurich had to spend the night in the Swiss city because the crew ran out of hours. They are expected to fly back at lunchtime, around 20 hours late. The aircraft was due to be operating the 6am departure from Gatwick to Lanzarote, which has been delayed for nine hours – along with the inbound flight.

Hundreds of passengers on British Airways flights from various parts of Europe are still waiting to be flown home. Outbound flights from London Heathrow to Prague and Olbia were so late on Wednesday that they could not operate back to the UK. They will be flying in on Thursday afternoon, along with a British Airways flight from Tirana that diverted outbound to Frankfurt due to a medical emergency.

Tara Cobham31 July 2025 09:47

Explained: What caused the air traffic outage?

The latest failure at Nats, the main air traffic control provider, led to dozens of diversions and cancellations – particularly affecting London Heathrow and Gatwick airports.

British Airways has cancelled a number of flights this morning to Heathrow, while easyJet says it has been rebooking disrupted passengers on alternative flights after multiple cancellations. Ryanair has once again called for the resignation of the Nats chief executive.

The Independent’s travel correspondent Simon Calder addresses the key questions and answers:

Tara Cobham31 July 2025 09:45