What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) The aircraft N636PB, a RW162F helicopter was being operated on an instructional flight. At approximately 0.6 hours into the flight the aircraft lost power due to failure of an exhaust valve rocker arm and attendent retainer spring. The aircraft was at approximately 1500 feet at the time of the power-plant failure. The pilot initiated an autorotation to an open field. The autorotation terminated in a nose low, hard landing. The helicopter subsequently rolled onto its left side. Damage to the aircraft was substantial.
As the FAA filed it
(-23) THE AIRCRAFT N636PB, A RW162F HELICOPTER WAS BEING OPERATED ON AN INSTRUCTIONAL FLIGHT. AT APPROXIMATELY 0.6 HOURS INTO THE FLIGHT THE AIRCRAFT LOST POWER DUE TO FAILURE OF AN EXHAUST VALVE ROCKER ARM AND ATTENDENT RETAINER SPRING. THE AIRCRAFT WAS AT APPROXIMATELY 1500 FEET AT THE TIME OF THE POWER-PLANT FAILURE. THE PILOT INITIATED AN AUTOROTATION TO AN OPEN FIELD. THE AUTOROTATION TERMINATED IN A NOSE LOW, HARD LANDING. THE HELICOPTER SUBSEQUENTLY ROLLED ONTO ITS LEFT SIDE. DAMAGE TO THE AIRCRAFT WAS SUBSTANTIAL.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.