Frontier Airlines ATL Terminal Operating out of Terminal N, sometimes referred to as the North Terminal, at Hartsfield-Jackson Atlanta International Airport (ATL) is Frontier Airlines. Domestic travel is the main use of Terminal N, where Frontier provides a selection of reasonably priced flights to numerous locations. The terminal has all the necessities, including places to eat, retail stores, and customer service desks. Before going to the gates in Concourse T, where Frontier's aircraft normally take off, travelers should check in at the designated counters and go through security screening.