More than 66,000 passengers are expected to travel through the Cincinnati/Northern Kentucky International Airport over the Thanksgiving holiday, and officials have one piece of advice: Plan ahead. Many airlines, including Delta Air Lines, allow passengers to check in online and print or download boarding passes. Some also allow flyers to check baggage online before leaving home. But holiday travelers should still arrive at the airport early: generally, at least an hour before takeoff. Flyers are strongly urged to double-check with their airline.