Flights have now resumed at UK airports after a technical glitch in the National Air Traffic Service (NATS) systems caused more than 150 cancellations on Wednesday.

NATS said the radar-related issue was detected at 4.05pm and resolved within 20 minutes by switching to a backup system.

Despite the quick fix, airlines and passengers faced major disruption during one of the busiest travel periods of the year.

Ryanair’s chief operating officer, Neal McMahon, called the incident “utterly unacceptable” and demanded the resignation of NATS CEO Martin Rolfe, blaming “continued mismanagement” and a failure to learn from the August 2023 outage.

EasyJet’s David Morgan also criticised the repeat failure, saying: “It’s extremely disappointing to see an ATC failure once again causing disruption to our customers.”

Although flights are departing again, airlines have urged passengers to check with their carriers before heading to the airport.

NATS has confirmed the issue was not cyber-related and stressed that safety procedures were followed throughout.

As of 10pm on Wednesday, 84 departures and 71 arrivals were cancelled at UK airports, with London’s Heathrow experiencing the highest number of disruptions.

Several incoming flights were also rerouted to cities across Europe, according to aviation analytics firm Cirium.

EasyJet’s chief operating officer, David Morgan, expressed frustration over the situation, saying: “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.”

Airlines are seeking answers from UK air traffic control provider Nats after a technical glitch led to over 150 flight cancellations, causing major disruption for thousands of passengers on Wednesday.

A man whose plane was cancelled from Heathrow Airport after air traffic control provider Nats suffered a technical issue, said he was worried he would miss his brother’s wedding.

John Carr, a chiropodist from Stourbridge, was on his way to Norway with a group of friends to help set up his brother’s wedding, for which he is best man, when he found out after checking in his flight was cancelled.

The 35-year-old told the PA news agency from outside Terminal 3 he was stressed.

He said: “I’m pretty gutted. We’ve got loads of stuff in the suitcases to set up the venue, because we’re obviously flying to Norway. We’ve got the wedding rehearsal to do. It’s quite stressful.”

His friend James Hedges, also from Stourbridge, added: “We found out today; we’d already checked in and gone through the security checks.

“We were in the departures lounge, and we were literally sitting down having a burger when it came up on the (screen). Our flight was still showing as if it was leaving, and they were waiting to give us a gate and that that would be given at 4.45pm. When that time came around, it then switched to cancelled.”

Ryanair has called on Nats CEO Martin Rolfe to resign after a system failure has caused flight delays across the UK.

“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 disruptedm” said Ryanair COO Neal McMahon.

“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.

“If NATS CEO Martin Rolfe fails to resign on the back of this latest NATS system outage that has disrupted thousands of passengers yet again, then UK Transport Minister Heidi Alexander must act without delay to remove Martin Rolfe and deliver urgent reform of NATS’s shambolic ATC service, so that airlines and passengers are no longer forced to endure these preventable delays caused by persistent NATS failures.”

The Independent’s Whitehall editor Kate Devlin writes:

The disruption at British airports has been caused by systems being down for just 20 minutes, The Independent understands.

Passengers are experiencing major delays in the wake of the traffic control issues, which has seen planes grounded and planes diverted to other areas.

Travellers have been warned that continued disruption is expected and they should check with individual airports for advice.

The Independent’s travel correspondent Simon Calder writes:

Passengers on later flights on Wednesday face long delays as a result of the air-traffic control shutdown. For example, the afternoon flight from Lyon to Luton diverted to Paris CDG as a result of the UK airspace shutdown. It eventually arrived at 8.50pm, three hours behind schedule. The subsequent trip to Jersey was delayed three hours, with a correspondingly late return – instead of arriving at Luton from Jersey at 8.30pm, the expected time is close to midnight.

At Southend, easyJet’s flights from Faro was diverted to Bordeaux. An incoming plane from Gran Canaria ended up on the island of Jersey, and a round-trip to Amsterdam was cancelled.

London City airport was badly affected, with one British Airways flight from Glasgow returning to its starting place, and links to Rotterdam, Palma and Amsterdam cancelled.

We’ve heard from transport secretary Heidi Alexander, who said on X that she is aware of the technical issue which shut down air traffic control operations.

“I have been informed systems have now been restored but continued disruption is expected, and passengers should check with individual airports for advice,” Ms Alexander added.

Flight analysts Cirium have said 84 departures and 71 arrivals were cancelled across UK airports on Wednesday,

This brings the total 155, the BBC reported.

Most of these cancellations were at London Heathrow, with 29 departures and 17 arrivals.

But Cirium does not give a cause foe the cancellations in its data, so some may not have been related to the power outage.

A Briton who was on a flight from Oslo to London – which has turned around mid-air towards the Norwegian capital – is expecting “chaos” when the plane lands.

Tanya Goldhaber said she was two-thirds of the way to London when the pilot informed passengers that the flight would be turning back to London due to a radar issue – and lack of fuel.

“My child went into meltdown for a little while which wasn’t great but she’s sleeping now,” Ms Goldhaber told The Independent.

“It’s a plane full of Norwegian and British people so it’s actually very calm and stoic, but basically we have zero information from anyone about what’s going to happen when we’re on the ground – but I’d imagine it’s going to be chaos when we get to Oslo,” she added.

“They’re suggesting the plane will land and go back at 7pm but I’m not sure anyone believes that. So we may or may not be back in the UK this week, we’ll see – I would not recommend doing this with a four-month-old baby.”