Speaking from Ryanair’s operations centre in Dublin airport following the ATC failure which saw a quarter of all inbound and outbound UK flights cancelled on Monday (28 August), O’Leary said the airline has so far not received an explanation for the incident.
"It is sadly outside of our control," he said. "We have been in contact with UK Nats, but we still haven’t had any explanation from them about what exactly caused this failure and where their back up systems were.
"It’s not acceptable that UK Nats simply allowed their computer systems to be taken down and everybody’s flights get cancelled and delayed."
O’Leary said Ryanair will hope to be running normal operations by the end of Tuesday (28 August) after it was forced to cancel an additional 70 flights.