There's a very slim chance that their court petition for chapter 11 will be disallowed - this almost never happens. If their justification for bankruptcy doesn't hold-up or there is accounting shenanigans, it could, but typically in the court proceedings the company presents a plan for continuation of business which nearly 100% of the time involves delisting under the current stock symbol and a reissuing of new shares under a new symbol when they emerge from chapter 11. The court trustee must approve the plan before this happens. He may elect to force the company into chapter 13 (liquidation) if the business reorganization plan doesn't blow his skirt up. The stock symbol MESA will get the dreaded "Q" added to it in the meantime until the case is closed, and we can continue to trade the old stock hoping that a buyer may come along and snap them up out of bankruptcy and make us all wealthy. Unfortunately, I don't know of a single case where this ever happened and the shareholders were able to maintain their positions.
That being said, I'm definitely interested in investing in the new organization. I still believe strongly in the company and also believe they would do well to continue creating joint-ventures and should entertain the prospect of merging their assets and resources with Republic or Virgin America.
Hey, I can dream...