What happened
A solo student pilot was performing quick stop maneuvers when the aircraft entered an uncontrolled descent. While transitioning from a high hover at 30 feet agl to a low hover, the pilot reported that the helicopter began vibrating and yawing to the left. During this event, the flight controls became ineffective, causing the helicopter to enter a spin. The aircraft subsequently impacted the ground and rolled onto its side.
The investigation
Post-accident examination of the main rotor blades revealed modest chordwise striations and leading edge damage, along with a uniform upward bending deformation of approximately 20 degrees from root to tip. Regarding the tail rotor, one blade remained undamaged, while the other exhibited a 10-degree tip-inboard bend at the midspan. The engine was tested after the accident and ran smoothly, and investigators found no evidence of mechanical anomalies prior to the event.