They are already talking about building a statue of Chesley B. "Sully" Sullenberger. Lucrative book and movie deals could follow. But even though the death-defying pilot of Flight 1549 is being celebrated as a hero, he still faces an investigation by the National Transportation Safety Board that will critique his every action. That is one of the reasons, union officials say, why he has stayed quiet as his star has risen. "Until the NTSB says, 'He's a hero,' he's under investigation," said James Ray, a spokesman for the US Airline Pilots Association, which represents crews at US Airways. "The NTSB...