The Airbus A320
is the main airliner of Aer Lingus fleet in 2009
They fly 32 of them in January 2009.
All these airlines fly with 174 seats in one single class, just like Ryanair, their low-cost competitor at Dublin airport.
Images of the Aer Lingus A320: in the air
These airliners are regular visitors to Amsterdam
Besides these 32 Airbus A320 airliners Aer Lingus seems to have also 6 larger A321 in it's fleet
in 2009 with each 212 seats in a single class layout.