Accident Details
On October 27, 2018, at about 1800 central daylight time, a RotorWay International Exec 162F, registration N162RF, was involved in an accident near Passaic, Missouri. The student pilot reported no injuries. The helicopter was being operated as a personal flight under Title 14 Code of Federal Regulations Part 91.
The student pilot stated that before departure, fuel was added to full capacity and preflight checks were completed. He departed from the airport heading east. The helicopter climbed to about 500 feet above ground level at approximately 80 mph. After flying east for about 10 minutes, the main rotor rpm indication in the cockpit dropped to zero. The student pilot confirmed that engine rpm indications remained normal. He decided to perform an autorotation to an open corn field and lowered the collective. During the glide, he realized he might impact a fence at the intended landing area. He applied aft cyclic to avoid the fence, which altered his glide path. After flaring and applying collective for landing, the rear portion of the right skid contacted the terrain. This caused the helicopter to bounce, leading to loss of control. The helicopter came to rest on its right side. The student pilot executed an emergency shutdown and exited the helicopter without further incident. He contacted a friend for assistance using his cellular phone.
The helicopter sustained substantial damage to the main rotor system, fuselage, tailboom, and tail rotor system.
Postaccident Examination
A postaccident examination by the Federal Aviation Administration (FAA) revealed an electrical short in the main rotor rpm indicating unit. The short was located inside the case between pins 5 and 9, which corresponded to a black wire and a dark blue wire. The short was observed to travel through the circuit. After removing the connector from the indicator's circuit board, the short remained. When the black and dark blue wires were removed from the connector, the short was no longer present. No other anomalies were found in the airframe.
Pilot Equipment and Procedures
The student pilot wore a Gentex SPH-4B helicopter flight helmet during the accident flight, though it was not required by the manufacturer or the FAA. He had removed the visor assembly. He reported that the top of the flight helmet shell sustained scratches and impact marks from the accident sequence. He stated that he "would have been cut up pretty bad" without the helmet.
The RotorWay International Exec 162 Pilot Operating Handbook (POH) provides engine failure indications: a change in noise level, right yaw, and low oil pressure may be the first signs. The POH advises checking all instruments for anomalies during flight. The autorotation procedures include lowering collective fully, applying left pedal, adjusting cyclic for level attitude, adjusting collective to maintain rotor rpm within the green (100%), and achieving an airspeed of 65 mph (within 60-70 mph limit). According to the student pilot's statement, the helicopter was operating outside the shaded area of the height-velocity envelope published in the POH at the initiation of the autorotation.
The student pilot did not submit the National Transportation Safety Board Pilot/Operator Aircraft Accident/Incident Report Form 6120.1 although requested.