The pilot stated that the purpose of the flight was to perform a final rinse load on an avocado orchard they had been spraying that day. After finishing with the load, they began the short return flight back to the truck. The pilot maneuvered the helicopter in a shallow right turn over a steep hill with about 80-percent power. With the helicopter about 20 feet above ground level (agl), and about 5 feet above the treetops, it made an uncommanded yaw. The pilot maneuvered toward a flat area and simultaneously experienced a loss of rotor revolutions per minute (rpm). The helicopter settled into the trees on a 75-degree slope. He shut off the engine and egressed the helicopter.
The pilot further noted that the main rotor appear to cut surrounding trees, which were about 6-inch thick in diameter. He stated that helicopter had over 14 gallons of fuel on board.