What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
According to the company instructor he had demonstrated a simulated engine failure with an intended power recovery. This procedure involved rolling the throttle twist grip to the ground idle position. At approximately 200 feet AGL, the instructor attempted a power recovery by rolling the twist grip to the flight position. The instructor noted that the twist grip would not move and was stuck in the ground idle position. The instructor verified that the pilot under instruction was not holding the controls. As a result, a full down autorotation was performed in which substantial damage to the aircraft occurred. The damage included main rotor blade trailing edge delamination, a severed star flex arm, and separation of the fenestron assembly. No injuries or post crash fire was reported.
Post accident, both the instructor and pilot under instruction attempted to roll the twist grip to the flight idle position. According to the instructor, the twist grip would only move 1/4 of an inch and would not engage the flight idle position. The pilot under instruction stated that he was not able to roll the twist grip to the flight position even after substantial force was applied.
As the FAA filed it
ACCORDING TO THE COMPANY INSTRUCTOR HE HAD DEMONSTRATED A SIMULATED ENGINE FAILURE WITH AN INTENDED POWER RECOVERY. THIS PROCEDURE INVOLVED ROLLING THE THROTTLE TWIST GRIP TO THE GROUND IDLE POSITION. AT APPROXIMATELY 200 FEET AGL, THE INSTRUCTOR ATTEMPTED A POWER RECOVERY BY ROLLING THE TWIST GRIP TO THE FLIGHT POSITION. THE INSTRUCTOR NOTED THAT THE TWIST GRIP WOULD NOT MOVE AND WAS STUCK IN THE GROUND IDLE POSITION. THE INSTRUCTOR VERIFIED THAT THE PILOT UNDER INSTRUCTION WAS NOT HOLDING THE CONTROLS. AS A RESULT, A FULL DOWN AUTOROTATION WAS PERFORMED IN WHICH SUBSTANTIAL DAMAGE TO THE AIRCRAFT OCCURRED. THE DAMAGE INCLUDED MAIN ROTOR BLADE TRAILING EDGE DELAMINATION, A SEVERED STAR FLEX ARM, AND SEPARATION OF THE FENESTRON ASSEMBLY. NO INJURIES OR POST CRASH FIRE WAS REPORTED.
POST ACCIDENT, BOTH THE INSTRUCTOR AND PILOT UNDER INSTRUCTION ATTEMPTED TO ROLL THE TWIST GRIP TO THE FLIGHT IDLE POSITION. ACCORDING TO THE INSTRUCTOR, THE TWIST GRIP WOULD ONLY MOVE 1/4 OF AN INCH AND WOULD NOT ENGAGE THE FLIGHT IDLE POSITION. THE PILOT UNDER INSTRUCTION STATED THAT HE WAS NOT ABLE TO ROLL THE TWIST GRIP TO THE FLIGHT POSITION EVEN AFTER SUBSTANTIAL FORCE WAS APPLIED.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.