20010318003499A

(.19) On March 18, 2001, about 1800 hours PST, a Schweizer 269C helicopter N6123A, was destroyed when it collided with terrain and rolled over near Ojai, California. Sun air aviation LLC was operating the helicopter under the provisions of 14 CFR part 91. The private pilot was not injured and two passengers sustained minor injuries. The local personal flight departed camarillo, California, about 1640. Visual meteoroological conditions prevailed. No flight plan had been filed. The primary wreckage was at 34 degrees 28.51 minutes north latitude and 119 degrees 23.90 minutes west longitude. In a wtitten statement the pilot stated that he WA sin cruise at 4,700 feet, and planned to fly along a ridgeline northwest of lake casitas. As he approached the mountain top, the nose suddenly veered to the left, and he heard several coughing sounds from the engine. He entered an autorotation, but could not reach the flat mountain top. The helicopter collided with terrain, hit trees, and rolled over. He secured the fuel shutoff valve, pulled the mixture control out and turned the battery and ignition switch off. He observedfuel leaking from the helicopter as he and the passengers exited the wreckage. (-23)during cruise flight, shortly after leveling off from climb, the rotorcraft suddenly yawed left and the pilot heard the engine cough. The pilot entered autorotation. Upon approaching the surface he flared and increased colletive to cushion touch down. The nose yawed right prior to touch down in the bushes. One passenger experienced a minor injury to his ankle. This aircraft has an engine over speed governor which sometimes reduces power abruptly. During level off acceleration following climb the RPM will increase until limited by the pilot or governor. A sudden reduction of power/torque will cause left yaw. The right yaw at the bottom of the autorotation as collective is raised indicates the engine was still producing power.