Background
A student pilot, under the supervision of a flight instructor, initiated a practice straight-in autorotation on a southerly heading. The maneuver was begun at 700 feet above ground level (agl) and an airspeed of 70 knots.
Accident Sequence
The flight instructor reported that the approach angle and descent grew quite steep very quickly. As the rotor rpm decayed to approximately 95% at an altitude of about 200 feet agl, the flight instructor initiated a go-around by rolling on the throttle, lifting the collective, and applying forward pressure on the cyclic while maintaining 60 knots as the helicopter continued to descend. The flight instructor then initiated a hard flare to stop the rate of descent, but the descent was slowed, not stopped. The instructor leveled the helicopter and executed a run-on landing at approximately 30 knots. Subsequently, the helicopter landed hard on soft terrain, rolled over, and came to rest on its left side. The flight instructor further reported that the left skid "hooked on an obstruction" prior to rolling over.
Post-Accident Examination
Examination of the accident site revealed there were no obstructions or obstacles near the main wreckage. A ground scar was found at the point of initial impact consistent with the length of the skid and was approximately one inch deep.