To work on my investing strategies I'm wanting to learn more about how to recognize failing companies such as spirit airlines to avoid making mistakes if I choose to pursue more active investing in the future. I've got the financial statements from 2019 to 2023 for spirit airlines ([ https://www.annualreports.com/Company/spirit-airlines-inc](https://www.annualreports.com/Company/spirit-airlines-inc) )and plan to compare financial statements to other airlines that have not gone bankrupt. I don't intend on investing in any airline, but I'm just doing this as a learning experience and would like to know what kind of things I should look for and what kind of things would not be obvious from the statements such as other actions that the ceo has made or did not make that lead to the demise of spirit airlines.