A 24-hour strike by Aer Lingus cabin crew is underway at Shannon, Cork and Dublin Airports.
The strike, which began at midnight, is in response to an ongoing row over rosters.
On the Friday of a bank holiday weekend Aer Lingus would normally carry around 40,000 passengers, but most of today's flights have been cancelled.
This includes 12 services between Shannon and the US, Faro and Heathrow. An additional return service to Faro has been added to the schedule for tomorrow, as the airline looks to accommodate passengers, but it's estimated that today's action will still cost the former flag carrier up to 10 million euro.
Pickets have been placed on the three State Airports since midnight, with around 120 Shannon-based cabin crew involved in the dispute.
Later this morning, Impact members will march through Dublin Airport to Aer Lingus headquarters, to hand in a letter to management explaining their problem with the rosters system.
Members of the pilots union IALPA are expected to march in solidarity with their colleagues.
Impact has accepted an invitation from Aer Lingus to talks, and while a date hasn't set, it's expected these will be held next week.
