What happened
While performing a long-line operation, the pilot was approaching a specific area of terrain to place a heavy load. During this maneuver, the helicopter entered a vortex ring state, also known as settling with power. This condition caused the aircraft to descend at a rate that the pilot could not arrest, leading the helicopter to strike the ground. Upon contact with the terrain, the aircraft's skids hit the surface and the helicopter bounced back into the air.
The investigation
During the examination of the aircraft, it was determined that at the moment the skids contacted the ground, the tail rotor struck a portion of the rigging used for the long-line load. This impact resulted in substantial damage to both the tail rotor and the tail rotor drive shaft.