Accident Sequence
The pilot reported that while beginning his approach to a landing site at an elevation of 5,200 feet, he felt a bump in the tail rotor pedals. The helicopter began to spin to the right and the pilot found he had no tail rotor control. An autorotative landing was made into the treetops, which the pilot estimated to be 125 feet above the mountain terrain. The main rotor mast separated after contacting the trees, and the helicopter rolled inverted and struck the ground in a nose low attitude. A small postcrash fire was extinguished by a portable fire extinguisher from the helicopter.
External Load and Strap Entanglement
Before the accident, the helicopter was being used on an external load operation. An investigation revealed that it was carrying a 30-gallon bucket that had been loosely filled with fabric strap. Witnesses reported the aircraft was descending at approximately 40 knots when they observed one or more of the straps trailing from the bucket. Subsequently, a strap became entangled in the tail rotor, and the tail rotor was observed to have stopped rotating.