It comes as the carrier has been forced to cancel thousands of flights
Ryanair has confirmed it has offered pilots bonuses of up to €12,000 if they agree to give up annual leave entitlements.
It is seen as a move to plug gaps in its flight schedule, which will see up to 50 flights cancelled per day for several weeks.
A number of flights to and from Dublin have been affected by the latest round of cancellations.
Six flights to and from the capital are among several affected on Tuesday - including services to Berlin, Glasgow and Krakow.
The Irish carrier has published the full list of flight cancellations for the next five weeks.
It says the cancellations have been allocated, where possible, to Ryanair’s bigger base airports and routes with multiple daily frequencies.
Customers affected will be e-mailed with offers of alternative flights or full refunds.
Ryanair says the cancellations are due to several factors, including a backlog of holiday leave to pilots and cabin crew.
The company is moving its holiday year from the current system of April to March to a calendar year of January to December from January 2018.
It says the backlog of crew leave must be allocated before December 31st.
However the company is now offering pilots who opt-out of their holiday entitlements to a bonus worth up to €12,000.
Ryanair says it "sincerely regrets and apologises for these cancellations".
The Commission for Aviation Regulation says it wants all passengers affected to be aware of their rights - more information is available here.