Customers were delayed across the UK on Monday (28 August) after Nats, the UK’s air traffic control provider, discovered an issue with its automatic system which provides controllers with details of every aircraft and its route.

According to aviation analytics firm Cirium, 790 flights departing the UK – which represents 27% of all departures – were cancelled due to the technical glitch, as well as 785 inbound services. Despite the issue being resolved within hours, delays are expected to continue into the coming days.

NATS operations director Juliet Kennedy apologised for the impact to people’s travel but advised it will "take some time" for fights to return to normal.

"Our absolute priority is safety and we will be investigating very thoroughly what happened today," she added. "I would like to apologise for the impact on the travelling public and our team will continue to work to get you on your way as soon as we can."

Rob Bishton, interim chief of the UK Civil Aviation Authority (CAA) said: "We understand the challenges many consumers continue to experience when flights are delayed or cancelled following yesterday’s technical issue that impacted NATS flight planning system. 

"Passengers who continue to be impacted can find information about what they are entitled to on our website. In the event of delays or cancellations, passengers will be expected to be provided with food and drink as well as accommodation if delayed overnight."

As part of the CAA’s regulatory oversight of its activities, the authority will continue to engage with NATS and once its investigation is fully complete, an incident report will be completed, with the outcomes shared with transport secretary Mark Harper.

Airports

Heathrow confirmed on Tuesday (29 August) there may be some continuing 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 the airport and for those passengers who need to rebook to contact their airline directly rather than travelling to Heathrow," it advised.

Gatwick said it plans to operate a normal schedule on Tuesday (29 August) following the disruption, but advised passengers to check the status of their flight with their airline before travelling to the airport.

Elsewhere, Edinburgh airport said disruptions to flight schedules remain and Birmingham airport confirmed operations are starting to stabilise, but a number of flight cancellations and delays have impacted customers.

Liverpool John Lennon said although the country-wide flight planning systems failure has now been resolved, there will be a knock-on effect causing some delays and cancellations.

On Tuesday morning (29 August), Manchester airport confirmed there continues to be some delays and cancellations and advised passengers to check the status of their flights before travelling to the airport.

"As our airlines look to accommodate passengers whose travel plans have been disrupted over the past 24 hours, our terminal may be busier than usual at times," a spokesperson said.

Airlines

Speaking on Tuesday morning (29 August), Ryanair chief executive Michael O’Leary confirmed the airline has been forced to cancel a further 70 flights due to the technical malfunction.

"We had a very difficult day yesterday," he said. "I am sad to report we had to cancel about 250 flights, affecting around 40,000 passengers, because of long delays to flight plans and crews running out of hours."

British Airways confirmed its flights continue to be severely disrupted as a result of the glitch. It advised passengers to not travel to the airport without checking the status of their flight, as it may be delayed or no longer be operating.

Any customers due to travel with BA on a short-haul service on Tuesday (29 August) or Wednesday (30 August) can move their flights free of charge to a later date, subject to availability.

Tui, meanwhile, said those affected by the disruptions could either amend their holiday for free to any other Tui package available with an up to 10% discount off the new holiday cost if it is more expensive, as well as a £100 per person Tui holiday voucher.

Jet.com confirmed all flights departing and returning to the UK are expected to experience significant delays. As a result of the disruption, the carrier has taken the decision to cancel some outbound flights scheduled for Tuesday (29 August).

Easyjet is providing customers on cancelled flights with the option to transfer their service free of charge or receive a refund. Customers due to travel tomorrow should travel to the airport as normal, Jet2 said, unless the company advises otherwise.