Bell 47D1 crash near Clanton, AL, United States

The flight instructor reported that while conducting an approach to landing, terminating at a three foot hover, the student pilot "pulled back on the cyclic and dumped collective", which caused the main rotor blades to contact the tail boom after the helicopter impacted the ground "hard". The flight instructor reported there were no pre-impact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. The helicopter sustained substantial damage to the tail boom and to the empennage.