Passengers check in at the Spirit Airlines counter at the Fort Lauderdale-Hollywood International Airport on February 07, 2022 in Fort Lauderdale, Florida. Joe Raedle | Getty Images Spirit Airlines, an icon of budget air travel that reshaped the industry, has filed for bankruptcy protection after years of mounting losses, a failed merger and more demanding consumer tastes. The carrier early Monday said it reached a prearranged deal with its bondholders