The High Court has granted an injunction preventing industrial action at Dublin, Shannon and Cork airports ahead of St Patrick's Day.
The Dublin Airport Authority and Ryanair argued that Siptu's planned four-work work stoppage this Friday as part of a pensions row would cost them millions of euro and cause disruption to thousands of passengers.
The proposed industrial action was over cuts to pension benefits at Aer Lingus and the DAA.
Declan Kearney from Aer Lingus said the airline might still experience disruption.
"We're a little over 36 hours away from the time of the dispute. We still don't know whether SIPTU intends to go ahead with the dispute in Aer Lingus," he said.
"Ultimately, customers and Aer Lingus can't wait around…We have rearranged our schedule for the day because ultimately, we can't deal with this level of uncertainty."