RYANAIR HAS REVEALED around 63,000 of its passengers saw their flights cancelled during last week’s air traffic control failure in the UK which caused widespread disruption across the industry and left thousands of passengers stranded overseas.

In its August traffic update, the carrier said more than 350 of its flights were cancelled on 28 and 29 August due to the air traffic control (ATC) issue.

More than a quarter of all flights to and from UK airports were cancelled on Monday, 28 August as the UK’s National Air Traffic Services (NATS) were unable to process flight plans automatically.

The knock-on effect continued for two more days and is said to have wrecked the travel plans of around a quarter of a million people.

Ryanair said the ATC failure “has still not been explained”.

Airlines have been infuriated by the incident, which came at one of the worst times of the year, with little spare capacity across the sector due to it being the end of the summer break for many schools.

Ryanair chief executive Michael O’Leary last week criticised NATS, calling the disruption “unacceptable”.

In a video message, the group’s boss described Monday as “a very difficult day” and hit out at NATS for failing to adequately explain what caused the failure and questioning why back-up systems did not kick in.

Rival easyJet’s chief executive Johan Lundgren also last week demanded that a “full independent review” is launched into the failure and said it “must not happen again”.

NATS has said an “unusual piece of data” it received forced it to switch to manual checks.

Ryanair’s latest traffic update showed it carried 18.9 million guests in total last month, up 11% on a year earlier.