Questions linger in Delta's purchase of Trainer refinery

When Delta Air Lines decided to buy the idled Trainer refinery outside Philadelphia to keep itself supplied with jet fuel, the announcement was met with a mix of skepticism, outright disbelief, and nods of approval from experts who follow the airline industry and oil and energy markets.Delta's move was smart, risky, insane, stupid, even brilliant — or all of those. "Is there a better investment than a refinery? Maybe not," wrote airline analyst Helane Becker in a client note.