NTSB Factual Report

The pilot herded cattle into a cattle trap and landed to close and adjust some gates, with the intent to take off again. The pilot left the engine running and exited the helicopter. While the pilot was outside the helicopter several cattle "spooked", one of which jumped a fence and came in contact with the main rotor, causing the helicopter to bounce and shake violently. A number of other cattle broke free from the pen and at least one contacted the helicopter, causing it to become airborne for a short period of time before impacting the ground in a nose low attitude. The tail boom and main rotor mast were both partially separated from the fuselage.

NTSB Probable Cause

The pilot's decision to exit the helicopter with the engine running.