Cause of Flight 3407 Crash Still a Mystery

The information released on Wednesday indicated that the airplane, a twin-engine turboprop Bombardier Dash 8 Q400, operated by Colgan Air for Continental, crashed because it experienced an aerodynamic stall — meaning that the combination of airspeed and the wings’ angle to the wind resulted in a loss of lift. The stall appears not to have been caused by “the light to moderate icing” likely present on the airplane.

The icing “had a minimal impact on the stall speed,” the update said, adding, “The airplane continued to respond as expected to flight control inputs throughout the accident flight.”

Rather, the stall appears to have been caused by upward movement of the nose, according to airplane performance modeling and simulation efforts. The investigation indicated that the nose rose when one of the two pilots pulled back on the control yoke with a force of 25 pounds, activating a moveable section of the tail that pushed the tail down and the nose up.

See here and here and here for significance.