Chap 11 presents many problems to the carriers who are not operating under Chap 11 bankruptcy rules. For example, until and IF the pilots of Delta argee to wage concessions, Delta will be paying its pilots about 40% more salary than is United.
Delta has to pay its aircraft acquisition costs whereas UA and US Air might be able to defer these costs. But most likely, in the end, UA will not be there too much longer to compete, for it sounds like the management and employees just distrust each other too much to ever row the boat in the same direction.