The pilot was undertaking his second flight for the day. His intention was to locate some stock on a property and on sighting a flock of sheep he descended to a very low height. While manoeuvring at this height the rotor rpm and airspeed decayed, and the pilot found that the aircraft had insufficient performance to clear a fence. The aircraft struck the fence and cartwheeled. The pilot and the seat/fuel tank were thrown clear of the wreckage, but the pilot sustained severe head injuries when he was struck by a rotor blade, despite the fact he was wearing a crash helmet. The aircraft was not fitted with a tachometer to indicate main rotor rpm, and the pilot had to rely on rotor noise to judge the speed.
