The pilot and passenger were enroute to Hastings to make an aerial inspection of a boat which the two men were considering buying. The aircraft was in cruising flight at a height estimated to be between 200 and 500 feet above ground level. A number of witnesses reported that the engine made a spluttering noise, followed by a bang. Pieces were then observed falling from the aircraft, and some witnesses saw the tail rotor assembly detach. The helicopter then dived to the ground and was destroyed by the impact and a fierce fire which broke out immediately afterwards. The subsequent investigation was hampered by the extent of the fire damage. No defect or malfunction was discovered which might have contributed to the apparent loss of engine power, and the reason for this loss remains undetermined. The pilot had relatively limited experience in helicopter operations, and had not flown the particular type for about 3 months. It was considered possible that when confronted with the power loss, the pilot may have applied abrupt control movements. These movements led to the main rotor blades striking and severing the tail boom, with a consequent loss of control of the aircraft.