if your travelling aer lingus to NY and not able to check in on line , then let me tell you,, before 6am in the morning there is no check in staff, not even to take the bags for the bag drop desk, you must wait till 6am for the staff to come in,, and the flight leaves at 645 for dublin and onwards to the usa then,
SNN is nice , and an easy airport to navigate, get thru