Delta Pilots May Have Had Enough

The question remains as to whether the contract will be ratified, Miller said, because pilots are so dissatisfied. "Even if Delta has solved the financial issues, they have not solved the distrust," he said.

Part of Delta's dilemma is that while pilot concerns must be addressed, the airline also has to meet the expectations of other employees who have made concessions, said Standard & Poor's credit analyst Philip Baggaley.

"Delta's other major employee groups are not unionized (excepting some groups at Comair), and have already taken cuts in pay and benefits," Baggaley wrote in a recent report.

"However, a concessionary pilot contract that falls well short of what management had sought could cause friction between the pilots and other employees, and make it more difficult for Delta to attract financing to exit bankruptcy," he continued. "In addition, such an outcome would encourage other employee groups to join unions to improve their bargaining position in future."

As for Comair, Miller said its employees have few options. "Comair is a high-cost operator in a business with razor-thin margins," he said. "If Comair can't get a cost structure that is competitive, there are regional airlines who can replace Comair."