Incident Details
During a low-level flight maneuver, a helicopter was transitioning from a downwind hover to forward flight. At an approximate altitude of ten feet above ground level and a forward airspeed of ten knots, the aircraft suddenly rotated quickly to the right.
Sequence of Events
The pilot attempted to recover from the unexpected rotation and was able to achieve a partial recovery. However, control of the helicopter was subsequently lost. The aircraft then descended towards the right side, eventually impacting the runway surface.
Actions by Personnel
An inspector pilot, who was also present in the helicopter, reduced the throttle slightly when the pilot first lost control. Just prior to the ground impact, the inspector pilot moved the throttle to the off position.