At least five Aer Lingus flights will not leave Dublin Airport today because of Covid cases among staff.
Trips to Hamburg, Berlin and three to London Heathrow have been cancelled so far.
Six return flights, due to depart from Dublin Airport, were also called off yesterday.
Travel writer Eoghan Corry says it's a widespread problem across the industry, as seen previously in Dublin Airport's security section.
He's expecting more short-haul flights to be cancelled today, meaning many people will be in the airport before they know their flight status.
The travel expert says those travelling on long haul flights will get 24 hours notice if they're flight is cancelled.