That, in the short term, customers probably wouldn't notice any difference. Stock, bond, and debt holders, vendor partners and the employees are the ones who would feel the brunt of the bankruptcy.

In the longer term, routes would almost certainly be cut, service levels would be pared down, and the AAdvantage program would be changed, but I can't imagine anything too drastic. AA would still have to remain competitive with UA and DL (and to lesser extents AS, B6, and US). They aren't going to become NK overnight.