Another low cost airline is coming to the Trenton-Mercer Airport. Allegiant Air will be coming to the airport beginning in Nov. The company plans to send flights to Florida and Punta Gorda. There will be special introductory fares beginning as low as $39 until July 30. The airport already has Frontier Airlines. Officials say initial discussions began about six months ago to bring an additional airline into the airport but it has just made it official.