Ryanair's facing widespread disruption across Europe today, with strike action in five countries including Ireland.
Dublin-based pilots are walking off the job for a fifth day - joining colleagues in Germany, Sweden, the Netherlands and Belgium.
Almost 400 flights have been cancelled affecting tens of thousands of passengers.
Bernard Harbor from the FORSA trade union says both sides are still some way off reaching a deal.
"We believe that this is a problem that can be resolved through negotiations.
"But I have to say that the experience of pilots so far is that the company's not been prepared to really grapple with the issues - and that's why they feel that they've been forced into yet another day of strike action today".
In a statement, Ryanair says: "Ryanair took every step to minimise the disruption and we notified our customers as early as possible advising them of their free move, refund or reroute options.
"The majority of customers affected have already been re-accommodated on another Ryanair flight.
"We want to again apologise to customers affected by this unnecessary disruption and we ask the striking unions to continue negotiations instead of calling anymore unjustified strikes".