Travel chaos caused by 'flight data received' by air traffic services

The air traffic control failure that grounded hundreds of flights was caused by a complex technical issue, the National Air Traffic Services (Nats) boss has said.

It left tens of thousands of people stranded on Tuesday and into Wednesday, as travel chaos - which began on Bank Holiday Monday - continued.

EasyJet announced it will run five repatriation flights to London Gatwick, with the first two set to take off on Wednesday.

Nats chief executive Martin Rolfe said "flight data received" by the UK's leading air traffic control provider caused the problem - and added there are no "no indications" of a cyber attack.

This caused a technical issue, so Nats' programmes responded by suspending the automatic system which usually inputs flight data.

Nats chief executive Martin Rolfe said: “Very occasionally technical issues occur that are complex and take longer to resolve.

"In the event of such an issue our systems are designed to isolate the problem and prioritise continued safe air traffic control.

"Initial investigations into the problem show it relates to some of the flight data we received.

“Our systems, both primary and the back-ups, responded by suspending automatic processing to ensure that no incorrect safety-related information could be presented to an air traffic controller or impact the rest of the air traffic system.

"There are no indications that this was a cyber-attack."

Mr Rolfe has apologised for the incident and has said all of the Nats systems have been running normally since Monday afternoon.

What caused the system to go down?

Nats has said the system went down due to flight data that it received.

Here is a step by step of what happened, according to Mr Rolfe:

  • Flight data was received by Nats;

  • A technical issue began, which was 'complex and difficult to resolve';

  • Nats' primary and back-up systems suspended automatic processing - this was to ensure that no incorrect safety-related information could be presented to an air traffic controller or impact the rest of the air traffic system.

Initial reports suggested an inputting error from a French airline was to blame for the ATC issue, but this was not addressed in the statement.

When pressed on the possibility of such a theory, the prime minister's official spokesman did not rule it out, but said he would not "pre-empt" speculation before the CAA's investigation is complete.

Asked if officials would speak to counterparts across the English Channel, the spokesman said "you would expect them to be speaking regularly" with other countries "but I'm not aware of any specific conversations with French counterparts".

Aviation consultant John Strickland said the industry should seek to find a "better way to back up" the automatic ATC system, to reduce disruption in the face of a similar issue.

Speaking to ITV News, Melanie Waite said she feels 'disappointed and let down' by airline Jet2 after her flight home from Mallorca was cancelled

Independent review announced

Nearly 300 flights were cancelled on Tuesday as a knock-on effect from yesterday's technical fault, which grounded flights and left thousands of passengers stranded.

Transport Secretary Mark Harper announced an "independent review" into the air traffic control (ATC) technical fault, which he described as the most significant to hit airports in "nearly a decade".

He met with the Civil Aviation Authority, airlines, airports, trade bodies and Border Force on Tuesday to discuss what went wrong.

Speaking after the meeting, Mr Harper apologised for the incident and said: “My priority continues to be making sure passengers get where they need to be as quickly as possible.

“Airlines are clear about their responsibilities to their customers, and I stand ready to provide further appropriate support from the government should the industry request it."

Easy Jet said on Tuesday its flights are "operating as normal" and will run five repatriation flights to Gatwick with an additional 700 seats this week.

The airline said: “During this traditionally very busy week for travel, options for returning to the UK are more limited on some routes and so easyJet will be operating five repatriation flights to London Gatwick over the coming days from Palma and Faro on August 30, and Tenerife and Enfidha on August 31 and from Rhodes on September 1.

“We are also operating larger aircraft on key routes including Faro, Ibiza, Dalaman and Tenerife to provide some additional 700 seats this week.”

Ryanair boss Michael O’Leary slammed air traffic control (ATC) provider Nats for the “unacceptable” disruption caused over the past two days.

In a video message posted on X on Tuesday, the chief executive described Monday as “a very difficult day” with 250 flights cancelled, while a further 70 were axed on Tuesday.

He said: “It’s not acceptable that UK Nats simply allow their computer systems to be taken down and everybody’s flights get cancelled.”

On Monday, 790 flights departing UK airports were cancelled and 785 arriving flights, according to aviation analytics firm Cirium.

This equates to about 27% of all planned flights, it added.

'Absolute chaos'

Passengers stuck in the UK and abroad described the "absolute chaos" they had endured as a result of flight cancellations.

Melanie Waite told ITV News herself and her 11-year-old son were left stranded on the Spanish island of Mallorca when their Jet2 flight to England was cancelled on Monday.

Melanie Waite's 11-year-old son sleeping on the airport floor in Mallorca. Credit: Melanie Waite

She said they received "not much" help from the airline and were informed their flight had been scrapped by staff only when they arrived at their departure airport.

"There was a couple of ground crew there that some people from our flight approached and they told us 'just go to the luggage carousel, collect your luggage, your flight's cancelled'," she added.

Others who were left stranded by the travel chaos told of how it had disrupted honeymoons and end of summer getaway plans.

One man told ITV News: "We're waiting to have the cancellation on our phones, so then we can book the hotel, but on our phones it still says the flight's going.

"But they [airport staff] keep saying that [the] flights are cancelled. All flights are cancelled."

The disruption also left round 40 British athletes and staff stranded in Budapest, following the World Championships.

Some are now travelling from Hungary's capital directly to Zurich for the Diamond League meeting on Thursday, while UK Athletics is working to get other athletes back home, but do not yet know when they will return.

Travel expert Paul Charles explains what your rights are if you've had your flight delayed or cancelled

On Tuesday, a Heathrow spokesman said: "Schedules continue to be affected by yesterday's restrictions on UK airspace.

"While the majority of passengers will still be able to travel, there will unfortunately be some disruption on some routes, including flight cancellations.

"It is important for all passengers to check the status of their flight with their airline before travelling to Heathrow."

Gatwick said it plans to operate a normal schedule on Tuesday, but advised passengers to "check the status of their flight with the airline before travelling to the airport".

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