NTSB Factual Report

The pilot was maneuvering at low altitude to take pictures of his neighbor's business. Suddenly the helicopter's engine "raced free of load", the needles split and he began an autorotation. The aircraft landed with its right skid up slope, and the helicopter rolled onto its left side. The pilot's postaccident examination of the control panel revealed that he had inadvertently deactivated the aircraft's electric clutch by striking its overhead toggle switch with his head. The helicopter's main rotor blades, one tail rotor blade, right landing skid, left horizontal stabilizer, and the tail boom were bent. The landing skid on the left side collapsed.

NTSB Probable Cause

The total loss of engine power due to the pilot inadvertently deactivating the rotor drive clutch assembly. A contributing factor was the downhill terrain condition where he landed, which exceeded the slope limitations of the helicopter.