As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) THE AIRCRAFT WAS IN A HOVER WITH A 125 FOOT LONG LINE. THE PILOT DROPPED OFF A BATTERY AND HAD DESCENDED ABOUT 5 FT, THEN NOTICED A RAPID DESCENT AND THE RPM WAS DELAYED. ENTERED INTO AUTOROTION AND LANDED. THE PILOT ADJUSTED THE THROTTLETO IDLE AND SHUT THE ENGINE DOWN THE ENGINE WITH THE FUEL SHUT OFF. SOURCE OF THIS DECELL IS UNKNOWN.