In March, Spirit Airlines came out of bankruptcy protection in less than four months and entered a worsening landscape. Consumers were holding off booking flights and U.S. planes were awash in empty seats. Even the most profitable airlines cut the rosy financial forecasts they had issued at the start of the year.

Spirit Airlines Inc. borrowed $275 million via a revolving credit facility to avert a looming cash crunch that had threatened to cut off the company’s ability to accept credit card payments from customers.