New measures designed to minimise the disruption caused by volcanic ash from Iceland came into force at midday today.
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 hoped 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.
A union bid to overturn the injunction was heard today at Britain's Court of Appeal. A judgment will be passed down on Thursday morning.
