Summary
A pilot reported an uncontrolled right yaw while making an approach to a hover about 15 feet above ground level. Despite corrective inputs, the helicopter ascended and then descended hard onto sandy terrain, resulting in substantial damage.
Narrative
According to the pilot, during an approach to a hover approximately 15 feet above ground level, he applied power to arrest the descent. The helicopter then began to yaw to the right. The pilot added left anti-torque pedal and increased power, but the yaw continued and the helicopter ascended to between 50 and 75 feet. The pilot then lowered the collective and reduced power. As the helicopter descended through about 25 feet above ground level, he raised the collective for landing. Subsequently, the helicopter landed hard on sandy terrain along the shoreline of a lake.
Damage
Examination of the helicopter revealed that the tail boom and firewall sustained substantial damage.
Examination
No mechanical anomalies were noted during the examination of the helicopter.