Almost half of European flights may be delayed after computer failure

Scores of complaints have been made to airlines on social media after flights were delayed for a number of hours, in some cases with the planes already boarded. 

A spokesperson for the Dublin Airport Authority (DAA) said it was not clear how many flights to Dublin are affected. 

Dublin Airport later tweeted: "A systems failure @eurocontrol, the organisation that manages air traffic control services across Europe, may cause some delays to the flight schedule @DublinAirport. Passengers are advised to check latest flight information with their airline."

Eurocontrol, which is the international agency responsible for air traffic control across Europe, said the problem was a failure with the "enhanced tactical flow management system".

"Contingency procedures are being put in place which will have the effect of reducing the capacity of the European network by approximately 10pc," the Brussels based agency said.

"Further information will be provided as soon as possible."

The system is used to compare traffic demand with the available capacity of air traffic control sectors.

A spokesman for Ryanair said the airline was monitoring the situation.

Meanwhile, the UK's two busiest airports will also be hit with flight delays over the next three weeks as air traffic controllers introduce new technology.

Heathrow and Gatwick will suffer disruption as Nats replaces paper flight information strips with a digital system at its control centre in Swanwick, Hampshire.

The number of flights allowed to land at the London airports will be reduced while controllers gain confidence using the new system in a live environment.

Average delays at Heathrow could be 20 minutes as arrivals are limited to 80% of maximum capacity for 10 days from Wednesday.

This will be raised to 90% of maximum capacity for the following 10 days.

People living under flight paths will also be affected, as Nats has requested permission to land some planes "slightly earlier and slightly later than usual", reducing the overnight respite from aircraft noise.

Jamie Hutchison, director of Nats' Swanwick base, told the Press Association: "We know there will be a number of flights affected, particularly in the first 10 days.

"But for the majority of those flights we expect the delay to be minimal and travellers should not change their plans or travel later to the airport.

"We will be doing everything we can, in partnership with the airports and airlines, to minimise the impact on passengers."

Nats says the introduction of the EXCDS digital system is an important step in the modernisation of how the UK's airspace is managed.

It is part of a £700 million programme to cope with growing demand for air travel.

UK air traffic is expected to grow from 2.6 million flights last year to 3.1 million in 2030.

Mr Hutchison said: "Unless we make significant investment in modernising both our tools and our airspace then we are not going to be ready for the future demand we're anticipating."