The president of the Irish Airline Pilots' Association claims Aer Arann pilots are earning, on average, less than €30,000 a year.
Yesterday, it emerged that some 91% of pilots at the regional airline have voted in favour of strike action in a row over the terms of a pay freeze.
Pilots want a wage cut and pay freeze they agreed to four years ago to be reversed.
Staff have told the company they are walking off the job next Tuesday and Wednesday, and again on the 24th and 25th of this month - which could affect up to 16,000 customers.
Evan Cullen, president of IALPA, says many of Aer Arann's pilots earn less than the average industrial wage.
"The average, we estimate, is just below €30,000," he said. "I have provided some journalists with payslips - unfortunately they can't be published because they would give the identity of the pilots, not only in the name but also in the amounts.
"The average pilot in Aer Arann is earning less than the industrial wage."