The technical issue affecting UK air traffic control systems has been “identified and remedied”, as passengers face major delays at airports.
NATS, the country’s national air traffic controllers, said that it is now “working closely” with airlines and airports to manage the flights affected as efficiently as possible.
In an update, NATS said: “The flight planning issue affected the system’s ability to automatically process flight plans, meaning that flight plans had to be processed manually which cannot be done at the same volume, hence the requirement for traffic flow restrictions.
“Our priority is always to ensure that every flight in the UK remains safe and we are sincerely sorry for the disruption this is causing. Please contact your airline for information on how this may affect your flight.”
It added that engineers are carefully monitoring the system’s performance during the return to normal operations.
Thousands of passengers faced significant delays on Monday morning after technical issues hit.