The first transatlantic flights to Ireland touched down in Dublintoday after six days of crippling air travel shutdown.
The Irish Aviation Authority (IAA) said airlines would spend the first few hours moving aircraft and crews to meet the biggest demand and begin the painstaking task of clearing massive passenger backlogs.
Aer Lingus cancelled all flights to the UK and Europe up until 1pm while Ryanair has stuck to plans to halt all services between Ireland and Britain until tomorrow lunchtime.
It is expected to take three days to clear travel waiting lists and fly the tens of thousands of stranded passengers to their destinations.
"The IAA is satisfied that commercial air travel outside of the exclusion zone does not present a safety risk," the aviation agency said.
"Airlines and maintenance organisations have agreed to an increased regime of risk management, ash ingestion assessment, and maintenance inspections, to ensure that no threat is posed to passenger safety."
Aer Lingus said most of its transatlantic flights will take off today but warned a service from Dublin to New York and another from Dublin, via Shannon, to Boston have been cancelled.
The airline said it expects all its scheduled flights after 1pm will take off.
After almost a week of cancellations caused by eruptions from an Icelandic volcano the resumption of full services began on a phased basis late last night.
The IAA insisted restrictions would only stay lifted if there was no more significant volcanic activity, and provided the massive ash cloud did not move over the country again.
Meanwhile passengers were urged to contact airlines before travelling to airports for flights.
The lifting of restrictions came as a huge relief to the country's two leading airlines, who estimate to have lost more than €70m during the crisis.
Aer Lingus said it was losing about €5m and Ryanair €6m a day as 30,000 Irish people were marooned overseas praying for rain and southerly winds to disperse the huge ash cloud.
Press Association
The Irish Independent
