Accident Description
The pilot was maneuvering a helicopter over a boat race. The helicopter was flying over the start line at an altitude of approximately 400 feet AGL, maintaining a magnetic heading between 235 and 240 degrees. The pilot perceived the helicopter drifting north and east, and a turn was initiated. At that moment, the helicopter shuddered and snapped into a rapid right yaw. The pilot applied left antitorque pedal, but the helicopter continued to yaw through multiple 360-degree rotations while losing altitude.
Pilot Actions Before Impact
Just before the helicopter struck the water, the pilot pulled up on the collective control and moved the cyclic forward and to the right. This action was intended to help stop the main rotor blades. The helicopter subsequently impacted the water and sank.
Reference to Published Guidance
The Rotorcraft Flying Handbook states that a loss of tail rotor effectiveness (LTE) is characterized by an uncommanded yaw rate that does not subside without intervention, potentially resulting in loss of helicopter control. The handbook's recommended recovery technique includes applying full left pedal while simultaneously moving the cyclic forward to increase airspeed, and if sufficient altitude is available, reducing power.