Irish flights to Britain have been delayed by a computer glitch in the English air traffic control system.
The problem in the National Air Traffic Control Service in Swanwick, southern England, caused flight delays of up to two hours between Ireland and Britain.
The problem started this morning at 7 a.m. - peak hour for both internal and all transatlantic routes.
An Aer Rianta spokesperson said: "The system is now back online in the UK and delays are easing somewhat".
The spokesperson said delays of between one and two hours on flights out of Ireland can still be expected. The route most affected is the London route, especially to Britain’s largest airport, London Heathrow, but a knock-on effect will be felt on most of the other British routes.
Aer Rianta advice for passengers travelling today into or out of Britain is to turn up on time for flights and to contact the airlines for information on possible delays or cancellations.