N530JRMcdonnell Douglas Heli 369FF

During an instructional flight, the instructor reported that they were practicing simulated engine failures and power recovery autorotations. During the fourth practice autorotation, the pilot receiving instruction attempted to terminate the maneuver with power to a 5 ft above ground level hover. The pilot did not move the twistgrip throttle from idle power back to full open and began raising the collective. The helicopter “fell through” and experienced a hard landing onto a field. The helicopter bounced, touched down hard again and spun about 150° resulting in substantial damage to the tail boom and empennage. The instructor reported that there were no mechanical malfunctions or failures that contributed to the accident.