The airline says it will cancel as many as 50 flights a day for six weeks because it "messed up" when scheduling crew holidays.
"We believe these working conditions are leading to pilots leaving the airline after a few years to go work for other airlines".
Norwegian went the extra step of identifying that it had recruited 140 pilots from Ryanair this year alone prompting Ryanair CEO to make a freaky retaliatory claim that Norwegian had not recruited 140 of Ryanair's pilots and that Ryanair thought Norwegian didn't have the resources to "last the year".
"We make mistakes", he said.
O'Leary added that they are compensating for the rebooking of flights for their passengers who are eligible to receive compensation based on the European passenger rights legislation.
Mr O'Leary told the AGM that Ryanair was facing a "significant management failure" and the cancellations had cost the airline about 25m euros (£22m).More news: EUR USD Exchange Rate Fluctuates Ahead of Key Fed Policy Meeting
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He refused to discuss media reports that many pilots had turned down offers of a £10,600 (€12,000) bonus and instead demanded improved contracts.
As a result, the airline said it had to allocate annual leave to pilots in September and October. The reason for the planned cancellations was put down to the company not having enough pilots, as many had booked holidays for the autumn and early winter.
The offer comes in a memo to pilots from Ryanair's chief operations officer Michael Hickey.
When asked about reports the pilots were threatening industrial action Mr O'Leary said: "If you want and need to ask your staff to give up holidays no work to rule can alter that".
Separately, some Ryanair pilots have spoken to the about a "toxic" atmosphere and how they felt "undervalued". "The head of the company, Michael O'Leary, openly insults his pilots, and has consistently maintained a policy of heading off any attempt to achieve a collectively bargained contract".
The airline said it expects to have re-accommodated (or authorised refund requests to) over 95pc of the 315,000 customers affected by these cancellations by the end of the week.