Spirit Airlines, the largest ultra-low-cost carrier in the United States, announced on Monday that it has filed for Chapter 11 bankruptcy protection. The decision follows a series of financial setbacks, including a blocked merger with JetBlue Airways and persistent engine issues that have impacted its fleet availability. In a statement, the airline confirmed it has reached a prearranged agreement with a majority of its loyalty and convertible bondholders to restructure its debt and provide capital to support operations. Spirit expects to continue flying and processing tickets as usual throughout the legal process. Industry experts note that the filing highlights the intense pressure on budget carriers facing rising labor costs and increased competition from legacy airlines. The company aims to emerge from bankruptcy in the first quarter of 2025.