Incident Overview
A pilot was conducting a demonstration flight to familiarize passengers with a helicopter. After takeoff, the pilot proceeded northeast at an altitude of approximately 100 to 150 feet above ground level (AGL) and a speed of 80 knots. The wind was from the west at 25 knots, gusting to 30 knots.
Sequence of Events
After traveling about 3 miles, the pilot initiated a left turn toward a westerly direction using approximately a 30-degree bank. Just prior to rolling out of the turn, the helicopter began to rapidly lose altitude, and the forward and aft cyclic controls did not respond to the pilot's inputs. Subsequently, the helicopter impacted the ground.
A passenger reported that during the turn to the west, they felt a thump. The aircraft then began climbing, followed by a 360-degree spin to the right before the impact.
Investigation Findings
Post-accident examination revealed no pre-impact part failure or malfunction. The three servo actuators were tested and all functioned properly. Local pilots reported that winds in the area were often unpredictable due to rolling hills, which may have influenced conditions.
Pilot and Passenger Accounts
The pilot believed that the wind had shifted and that the helicopter may have turned downwind, leading to settling with power. The passenger's account described a different sequence, including a climb and a spin. The investigation did not determine a specific cause for the loss of control.
Conclusion
No probable cause was stated in the investigation report. The helicopter impacted terrain after a loss of control during a turn in gusty wind conditions.