Event Details
A pilot was demonstrating autorotative landings in a helicopter equipped with high skid landing gear. During the fourth autorotation, the pilot executed a straight-in approach and touched down on level, smooth terrain. As the helicopter was decelerating, the high skid rotated rearward, causing the helicopter to pitch nose down and slap the ground with sufficient force to activate the Emergency Locator Transmitter (ELT). The nose-down pitch also caused the tail boom to rise and strike one main rotor blade.
Pilot's Account
The pilot reported that the helicopter had touched down smoothly in a level attitude. He expressed the belief that the high skid needed to be strengthened to prevent such occurrences.
Landing Gear Design
Investigation revealed that the cross tube assemblies were not directly bolted at the fuselage attachment points. Instead, they contained nipples designed to resist rotation when properly secured to the fuselage.