Pilots at Emerald Airlines have issued the company with notice of industrial action over a trade dispute.
The carrier holds the regional license for Aer Lingus.
The Irish Airline Pilots Association, a branch of Forsa, says the action which began today, and will consist of a rolling work-to-rule.
That means not working off days and no overtime and the union also says it reserves the right to escalate that action.
IALPA says it was surprised Emerald Airlines did not engage with union reps.
