Pilots using rudders may have unwittingly conducted potentially dangerous maneuvers to control aircraft during turbulence, but the risk became clear only after the in-flight breakup of an American Airlines jet last year, a captain at American testified Wednesday while defending the carrier's training program. In the second day of a hearing into the crash of American Flight 587 last year in New York, the National Transportation Safety Board examined how the airline trains pilots to stabilize aircraft from lateral rolls or side-to-side movements that may place excessive stress on the tail fin.