Incident Overview
A check airman was conducting a night vision goggle (NVG) annual check ride for a pilot in command in an emergency medical service helicopter. The training session included slope landing and hovering autorotation maneuvers.
Sequence of Events
After a satisfactory slope landing, the pilot in command repositioned the helicopter to a flat area and performed a hovering autorotation, which resulted in a hard landing. The check airman then demonstrated a second hovering autorotation, and the pilot in command performed a third hovering autorotation, which was satisfactory. The check airman continued the annual check ride without any immediate indication of damage.
Post-Flight Discovery
Following the flight, during a post-flight inspection, substantial damage was discovered to the tail boom and the aft portion of the fuselage. The damage pattern was consistent with a hard landing, presumably incurred during the first hovering autorotation in which the helicopter landed hard.
Statement by Check Airman
In a statement provided to the NTSB, the check airman said that he should have guarded the collective more to limit the amount of control input during the practice autorotation maneuvers.