Final Report: U.S. Forest Service AS 350 collided with trees
Eurocopter AS 350B3, Yellow Pine, Idaho, Aug. 13, 2006–The NTSB determined that the U.S. Forest Service contract pilot’s intentional low-altitude flight and his failure to maintain an adequate altitude to clear the trees was the cause of the crash of the AS 350, which killed all four on board. The helicopter, which was transporting a relief fire lookout to a tower on Williams Peak, hit a 90-foot-tall, dead, defoliated tree as it flew over a mountain ridgeline. The power turbine’s blades were found sheared from their disc, indicating overspeed, consistent with a main rotor blade strike/sudden stoppage.
Four maintenance crewmembers who were assigned to the helicopter said the pilot liked to do “showy” flying and would “buzz” a ridge every now and then. He would perform a maneuver he called the “sleigh ride,” described as topping a ridge then dropping the collective, and dropping the nose…“It was a common maneuver for him,” one witness said.