Overview
A flight instructor reported that during an instructional flight, she and her student pilot were practicing autorotations. The incident occurred during a right-turn 180-degree autorotation.
Maneuver
As the maneuver progressed, the flight instructor announced that the throttle was coming on, and then when full throttle was applied. The student began leveling the helicopter. However, the wind had shifted during the maneuver, requiring the student to flare harder and use increased cyclic control.
Landing and Damage
To prevent an engine over-torque, the flight instructor took control of the helicopter and landed. During the landing, the tail boom sustained substantial damage.
Instructor's Report
The flight instructor reported no preimpact mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation.