Ryanair grounded 80 percent of its fleet from midnight last night due to travel restrictions across Europe.
The airline says it expects a further reduction next Wednesday which could leave only a skeleton service, most likely between Ireland and the UK.
Aer Lingus has not yet confirmed additional cuts after restrictions to its American schedules imposed by the US on Tuesday.
Bernard Harbour from FORSA, the union that represents many pilots and cabin crew, says they're in daily contact with airlines here to save jobs.
It's likely there will be an impact on peoples jobs and incomes. We're not quite sure what that will be in specific airlines yet
"But it's clear already from what the airlines are telling us and what they're saying publicly is that the sector will be hit very badly.
"We want to minimise the impact on cabin crew and pilot jobs. And we also want to ensure the industry is in as good a shape as possible to bounce back from this."
