Accident Details
A flight instructor reported that she was providing takeoff and landing training from and to a helicopter landing platform. During the landing, the student pilot had control of the collective and anti-torque pedals, while the flight instructor maintained control of the cyclic.
Sequence of Events
The flight instructor stated that during landing to the platform, "the student lowered the collective suddenly, and also pulled back up (on the collective) suddenly as well." Additionally, the student grabbed the cyclic and pulled aft when he increased the collective. The helicopter bounced on the platform and "tilted backwards." The helicopter then started to roll to its right side, and the instructor closed the throttle. The helicopter rolled onto its right side, and the main rotor blades struck the ground.
Damage
The helicopter sustained substantial damage to the main and tail rotor drive systems and the fuselage.
Additional Information
The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation.