Accident Overview
A Schweizer 269C helicopter, operated by a pilot on a non-revenue sightseeing flight to look for alligators, experienced an uncommanded right yaw while hovering. The incident occurred when the pilot entered an out-of-ground-effect hover at an altitude between 50 and 70 feet above ground level. The pilot oriented the helicopter into the wind, which was estimated based on water conditions. After approximately five seconds of hovering, the pilot pitched forward on the cyclic and raised the collective control.
Sequence of Events
Shortly after the control inputs, the helicopter began an uncommanded right yaw. The pilot responded by lowering the collective, applying forward cyclic, and using left anti-torque pedal inputs. Despite these actions, the yaw continued unabated. The helicopter completed at least eight full 360-degree turns to the right before the pilot managed to level the helicopter and raise the collective. The helicopter subsequently descended and came to rest upright in approximately two feet of water.
Damage and Injuries
No injuries were reported, and no property damage occurred. The helicopter sustained damage to its landing skids and cross tubes during the landing in the water.
Pilot Observations
The pilot believed the incident involved a loss of tail rotor authority and noted that no vibration was felt in the anti-torque pedals. He also remarked that nearby trees might have altered the wind direction around the helicopter. The reported wind near the accident site at the time was from 310 degrees at 7 knots.
Postaccident Examination
A postaccident examination of the helicopter did not reveal any preimpact mechanical malfunctions or anomalies.