What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) The CFI stated that while practicing a forced landing with power recovery, he did not turn the governor off. The trainee entered auto-rotation and rolled the throttle into detent to keep the needles split. At low altitude; not knowing that the trainee had rolled the throttle into detent. He tried to make a power recovery but was not able to because of resistance on the throttle. As a result, both the instructor and trainee were convinced they had an engine failure. The instructor took over, performed the auto-rotation but failed to maintain safe rotor RPM control and selected a tall grass area. The helicopter made ground contacts and subsequently rolled over. Neither trainee nor instructor was injured. The aircraft sustained substantial damage.
As the FAA filed it
(-23) THE CFI STATED THAT WHILE PRACTICING A FORCED LANDING WITH POWER RECOVERY, HE DID NOT TURN THE GOVERNOR OFF. THE TRAINEE ENTERED AUTO-ROTATION AND ROLLED THE THROTTLE INTO DETENT TO KEEP THE NEEDLES SPLIT. AT LOW ALTITUDE; NOT KNOWING THAT THE TRAINEE HAD ROLLED THE THROTTLE INTO DETENT. HE TRIED TO MAKE A POWER RECOVERY BUT WAS NOT ABLE TO BECAUSE OF RESISTANCE ON THE THROTTLE. AS A RESULT, BOTH THE INSTRUCTOR AND TRAINEE WERE CONVINCED THEY HAD AN ENGINE FAILURE. THE INSTRUCTOR TOOK OVER, PERFORMED THE AUTO-ROTATION BUT FAILED TO MAINTAIN SAFE ROTOR RPM CONTROL AND SELECTED A TALL GRASS AREA. THE HELICOPTER MADE GROUND CONTACTS AND SUBSEQUENTLY ROLLED OVER. NEITHER TRAINEE NOR INSTRUCTOR WAS INJURED. THE AIRCRAFT SUSTAINED SUBSTANTIAL DAMAGE.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.