Spirit Airlines has acknowledged that it may not be able to stay in business. The budget airline may face liquidation instead of another bankruptcy.

Just five months after emerging from Chapter 11 bankruptcy protection, Spirit Airlines is warning about its future ability to stay in business.

Little more than five months out of Chapter 11 bankruptcy, Spirit Airlines has served a brutal reality check — warning investors that now there is 'substantial doubt' about its ability to stay in flight after next year.