The Irish Air Line Pilots' Association (IALPA) has said it is aware of the latest Ryanair letter to pilots and is analysing the content for its members.
Ryanair Chief Executive Michael O'Leary wrote to pilots promising improvements to pay and conditions, including a commitment to benchmark pay against competitor airlines.
However, Mr O'Leary said the changes would only be secured by negotiation through the company's in-house Employee Representative Councils.
IALPA has said there are a lot of promises in the letter but no details of what the cost of these promises will be.
The association says its members had experienced Ryanair promises before and would need to carefully consider each point before deciding on a response.
In the letter, Mr O'Leary said the company would match and exceed the pay offered by other 737 aircraft operator airlines at any base where the Ryanair rate for pilots was lower.
He also said he was writing to apologise personally to each of them for the disruptions experienced to rosters as a result of the rostering management failure in recent weeks.
Mr O'Leary promises pilots a loyalty bonus up to €12,000 payable from next month, and promises pilots an improvement in the management of rosters, training, and base selection.
The British Airline Pilots Association has said feedback the union has got from pilots following the letter issued by the Ryanair CEO yesterday suggests that Michael O'Leary "still doesn't get it".
BALPA General Secretary Brian Strutton said pilots from bases all over the UK want their European Employee Representative Council to be the recognised representative body for Ryanair pilots.
He said until they were given that, Ryanair would have a problem with its pilots.
In a statement, Mr Strutton said: "Our feedback from Ryanair pilots who have seen Michael O'Leary's letter suggests that he still doesn't get it.
"Pilots from bases all over the UK have told us that they don't want half-hearted excuses to shut them up.
"They tell us that they want genuine respect and for their European ERC to be the recognised representative body for Ryanair pilots. Until they are given that, Ryanair will have a problem with its pilots."
Tánaiste and Minister for Business, Enterprise and Innovation Frances Fitzgerald also said she hoped that the situation involving pilot rosters at Ryanair would be resolved in the interests of consumers and in the interests of what she described as "a very important company".
She said Ryanair had democraticised air travel and any actions that would clarify the situation for customers would be welcome.