New measures designed to minimize the disruption caused by volcanic ash from Iceland came into force from midday today, RTE reports.
The Irish Aviation Authority and the UK's Civil Aviation Authority have jointly agreed a new fly zone that will allow aircraft to fly closer to ash clouds.
The decision was made on the basis of data collected from aircraft engines in the weeks since the volcano first erupted.
The IAA said the move will reduce flight restrictions in Irish and UK airspace in the coming months and will soon be sanctioned by authorities throughout Europe.
Around 1,000 flights were grounded across northern Europe yesterday due to the ash from the Icelandic volcano.
In a separate development, British Airways said it hopes to operate just over half its flights from Heathrow today after a strike by cabin crew was ruled illegal by the High Court in London.
The first of four strikes, lasting five days, had been due to begin last night.
However, a judge granted the airline an injunction to stop the strikes after ruling that members of the Unite union had not been fully informed about the strike ballot.
The union has said it will appeal the decision.