Incident Overview
During a long-line load placement operation, the pilot inadvertently allowed the helicopter to enter a vortex ring state, also known as settling with power. This condition resulted in the pilot's inability to prevent the helicopter from descending at a rate that caused it to strike the ground and bounce back into the air.
Sequence of Events
As the pilot approached an area intended for placing the long-line load onto the terrain, the helicopter entered the vortex ring state. The helicopter subsequently contacted the ground with its skids. At that moment, the tail rotor impacted a portion of the rigging attached to the load the helicopter had been hauling.
Damage Assessment
The impact between the tail rotor and the rigging resulted in substantial damage to both the tail rotor and the tail rotor drive shaft. The extent of the damage was significant, affecting the helicopter's tail rotor system.
Probable Cause
The incident occurred because the pilot inadvertently allowed the helicopter to enter a vortex ring state (settling with power) condition, resulting in his inability to keep the helicopter from descending at a rate that led to it hitting the ground.