A Spirit Airlines Airbus A320 taxis at Los Angeles International Airport after arriving from Boston on September 1, 2024 in Los Angeles, California. Kevin Carter | Getty Images News | Getty ImagesSpirit Airlines has warned it might not be able to survive as a going concern if it doesn't raise more cash, five months after the budget travel icon emerged from bankruptcy.After cutting its debt during restructuring, Spirit has tried to attract bookings by marketing more upscale products and looking for new ways to lower costs. Late last month, the...