At a height of about 80 feet above ground level with little forward speed, the helicopter suffered a complete power loss. During the subsequent autorotational descent the main rotor struck trees, and the right skid was torn off on impact with the ground. Investigation revealed that two connecting rods had become detached from the crankshaft, and the engine had seized. It was likely that a previous overspeeding of the engine had stretched the big end bolts. This led to a loss of torque on the nuts retaining the bolts, which finally suffered overload failures.
