Trenton-Mercer Airport is a hidden gem for people living in the area between New York City and Philadelphia who are looking for cheap flights to Florida. Trenton’s only airline is Frontier Airlines and in April it will operate four low-cost routes to different destinations in Florida. It has operated more routes in the past, but some of these have been terminated. Trenton Airport is one of the overlooked small airports serving the wider New York metropolitan area and it is planning a significant expansion.