What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) Flight instructor was giving advanced training to student. During straight in autorotation practice the descent had deteriorated to a point beyond recovery. The flight instructor did not react in sufficient time to abort the autorotation and initiate a go around. The helicopter remained upright, slid across a grass area and stopped. The main rotor blades struck the tail boom just aft of the anti collision light. The helicopter sustained substantial damage to the tail boom, main rotor blades and the main rotor power train system. There were no injuries. (.4) during an autorotation, the pilot made a hard landing and the tail boom was severed. The purpose of the flight was to conduct pattern work, and takeoffs and landings to prepare the private pilot for his commercial pilot practical test flight. During the flight the private pilot was on the flight controls, with the CFI monitoring the flight. No discrepancies were noted with the first two takeoffs and landings. During the first autorotation, the CFI noted that the student allowed the airspeed to fall below 60 knots, and that the rotor RPM was moving outside the top of the green arc. He inst ructed the student to maintain airspeed at 65 knots until close to the ground, and to raise the collective to maintain rotor RPM inside the green arc. On the second autorotation, the CFI noted that the student maintained rotor RPM inside the green arc, but let the airspeed fall below 58 knots. The low rotor RPM warning horn sounded and the caution light illuminated. Due to the close proximity of the helicopter to the ground, a flare for landing was initiated. The CFI came up on the controls and noted that the collective was higher than normal. Prior to touchdown the CFI applied forward pressure on the cyclic to maintain a level attitude after touchdown. The helicopter landed hard and slid across the ground before coming to rest in a grassy area next to the helipad. The CFI noted that after coming to a stop he attempted to move the anti-torque pedals, but did not receive a response.
As the FAA filed it
(-23) FLIGHT INSTRUCTOR WAS GIVING ADVANCED TRAINING TO STUDENT. DURING STRAIGHT IN AUTOROTATION PRACTICE THE DESCENT HAD DETERIORATED TO A POINT BEYOND RECOVERY. THE FLIGHT INSTRUCTOR DID NOT REACT IN SUFFICIENT TIME TO ABORT THE AUTOROTATION AND INITIATE A GO AROUND. THE HELICOPTER REMAINED UPRIGHT, SLID ACROSS A GRASS AREA AND STOPPED. THE MAIN ROTOR BLADES STRUCK THE TAIL BOOM JUST AFT OF THE ANTI COLLISION LIGHT. THE HELICOPTER SUSTAINED SUBSTANTIAL DAMAGE TO THE TAIL BOOM, MAIN ROTOR BLADES AND THE MAIN ROTOR POWER TRAIN SYSTEM. THERE WERE NO INJURIES. (.4) DURING AN AUTOROTATION, THE PILOT MADE A HARD LANDING AND THE TAIL BOOM WAS SEVERED. THE PURPOSE OF THE FLIGHT WAS TO CONDUCT PATTERN WORK, AND TAKEOFFS AND LANDINGS TO PREPARE THE PRIVATE PILOT FOR HIS COMMERCIAL PILOT PRACTICAL TEST FLIGHT. DURING THE FLIGHT THE PRIVATE PILOT WAS ON THE FLIGHT CONTROLS, WITH THE CFI MONITORING THE FLIGHT. NO DISCREPANCIES WERE NOTED WITH THE FIRST TWO TAKEOFFS AND LANDINGS. DURING THE FIRST AUTOROTATION, THE CFI NOTED THAT THE STUDENT ALLOWED THE AIRSPEED TO FALL BELOW 60 KNOTS, AND THAT THE ROTOR RPM WAS MOVING OUTSIDE THE TOP OF THE GREEN ARC. HE INST RUCTED THE STUDENT TO MAINTAIN AIRSPEED AT 65 KNOTS UNTIL CLOSE TO THE GROUND, AND TO RAISE THE COLLECTIVE TO MAINTAIN ROTOR RPM INSIDE THE GREEN ARC. ON THE SECOND AUTOROTATION, THE CFI NOTED THAT THE STUDENT MAINTAINED ROTOR RPM INSIDE THE GREEN ARC, BUT LET THE AIRSPEED FALL BELOW 58 KNOTS. THE LOW ROTOR RPM WARNING HORN SOUNDED AND THE CAUTION LIGHT ILLUMINATED. DUE TO THE CLOSE PROXIMITY OF THE HELICOPTER TO THE GROUND, A FLARE FOR LANDING WAS INITIATED. THE CFI CAME UP ON THE CONTROLS AND NOTED THAT THE COLLECTIVE WAS HIGHER THAN NORMAL. PRIOR TO TOUCHDOWN THE CFI APPLIED FORWARD PRESSURE ON THE CYCLIC TO MAINTAIN A LEVEL ATTITUDE AFTER TOUCHDOWN. THE HELICOPTER LANDED HARD AND SLID ACROSS THE GROUND BEFORE COMING TO REST IN A GRASSY AREA NEXT TO THE HELIPAD. THE CFI NOTED THAT AFTER COMING TO A STOP HE ATTEMPTED TO MOVE THE ANTI-TORQUE PEDALS, BUT DID NOT RECEIVE A RESPONSE.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.
Other reports on N8492A · 1
Matched to the same aircraft by N-number and date.