Spirit Airlines' Chapter 11 filing creates more questions than provides answers

Spirit Airlines' recent Chapter 11 filing was hardly surprising. The airline hasn't been profitable in years, and debt payments were looming large.

The airline has forged a pre-arranged reorganisation with bond-holders, and also released a turnaround plan that's arguably a business model shift away from the aggressive product unbundling that served Spirit well for many years.

But none of its planned changes are new or innovative in a market dominated by larger airlines, whose products will remain superior to Spirit's.

For now, Spirit's bond-holders seem willing to give the company time to execute on its plan; however, the airline's fate is far from certain.