What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) Instructor pilot stated that during practice autorotative descent, student allowed airspeed and rotor RPM to deteriorate in last 200 feet of glide. Instructor attempted a late recovery, while student was still manipulating controls, causing aircraft to strike the runway, severing the tailboom. The aircraft bounced a second time, and spun out of control on the runway surface edge until one of the skids contacted the dirt surface adjacent to the runway, causing the helicopter to come to a rest on its left side.
As the FAA filed it
(-23) INSTRUCTOR PILOT STATED THAT DURING PRACTICE AUTOROTATIVE DESCENT, STUDENT ALLOWED AIRSPEED AND ROTOR RPM TO DETERIORATE IN LAST 200 FEET OF GLIDE. INSTRUCTOR ATTEMPTED A LATE RECOVERY, WHILE STUDENT WAS STILL MANIPULATING CONTROLS, CAUSING AIRCRAFT TO STRIKE THE RUNWAY, SEVERING THE TAILBOOM. THE AIRCRAFT BOUNCED A SECOND TIME, AND SPUN OUT OF CONTROL ON THE RUNWAY SURFACE EDGE UNTIL ONE OF THE SKIDS CONTACTED THE DIRT SURFACE ADJACENT TO THE RUNWAY, CAUSING THE HELICOPTER TO COME TO A REST ON ITS LEFT SIDE.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.