Incident Overview
A certified flight instructor (CFI) and a student were practicing autorotative landings in a helicopter. The student had previously completed two practice straight-in autorotative landings with power recovery. For the third attempt, the student entered autorotation at 700 feet above ground level (agl) and 70 knots, with the main rotor and engine rpm needles "split" and the throttle in the detent.
Approach and Flare
During the approach, the student maintained 65 knots. At 40 feet agl, the student initiated a flare. The CFI noticed that the helicopter was drifting away from the taxiway centerline and advised the student to recover. The helicopter was leveled, and the CFI applied throttle slowly. While descending, the CFI heard the low rotor warning horn just before impact, and believed that the student pulled collective control just before touchdown.
Impact and Aftermath
The helicopter impacted the ground "hard" on its left side, spun to the right, and came to rest upright. The CFI stated that there were no mechanical failures or malfunctions to the helicopter or any of its systems. The student reported that the flare was normal and that the main rotor rpm remained in the green. The student noted that after leveling off, "...before we could roll the throttle back on, the left skid make contact with the ground."