What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
During flight pilot/cfi reduced throttle to demonstrate autorotation to student. Immediately following reduction of throttle, experienced engine failure resulting in the pilot performing poweroff rotation to ground. During termination of autorotation, as a result of lost rotorspeed the blades came in contact with the tail boom causing loss of tail rotor and gear box.
As the FAA filed it
DURING FLIGHT PILOT/CFI REDUCED THROTTLE TO DEMONSTRATE AUTOROTATION TO STUDENT. IMMEDIATELY FOLLOWING REDUCTION OF THROTTLE, EXPERIENCED ENGINE FAILURE RESULTING IN THE PILOT PERFORMING POWEROFF ROTATION TO GROUND. DURING TERMINATION OF AUTOROTATION, AS A RESULT OF LOST ROTORSPEED THE BLADES CAME IN CONTACT WITH THE TAIL BOOM CAUSING LOSS OF TAIL ROTOR AND GEAR BOX.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.