No-frills flying pioneer, Spirit Airlines (NYSE:SAVE) sought Chapter 11 bankruptcy protection on Monday as it struggled with ongoing debt payments, failed merger attempts, and continuous losses. Renowned for its distinctive yellow aircraft, the airline has seen rising operational costs even with strong travel demand. Its financial problems took a turn for the worse after a $3.8 billion merger proposal with JetBlue Airways fell apart in January. Many of its aircrafts were grounded because of problems with RTX's Pratt & Whitney Geared Turbofan engines.

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Monday's court document claims that Spirit declared assets and liabilities ranging between $1 billion and $10 billion. Spirit negotiated a $350 million equity investment and $300 million in debtor-in-possession finance to help it negotiate the bankruptcy procedure. Along with its cash reserves, the airline claimed these steps would help to keep operations running during restructuring.

Spirit reassured consumers that bookings and flights were intact and promised it would keep flying operations free from disturbance. Still, the company anticipates its shares to be delisted from the New York Stock Exchange in the not-too-distant future. As the budget airline tries to stabilize its financial situation and map a sustainable future, this filing marks a turning point in its history.

This article first appeared on GuruFocus.