What happened
During a cross-country training flight, a flight instructor and a student were performing an off-airport landing at an elevation of 4,500 feet mean sea level. The reported density altitude for the maneuver was 7,300 feet. As the helicopter approached the intended landing site, the aircraft began to yaw to the right, and the left pedal became ineffective.
The flight instructor took control of the aircraft and observed that the main rotor RPM was low. In an attempt to recover, the instructor lowered the collective slightly and applied additional throttle; however, the left pedal remained unable to turn the helicopter into the wind. The instructor subsequently lowered the collective again, allowing the helicopter to settle, and then pulled the collective to cushion the landing. During the maneuver, the main rotor made contact with the terrain and mesquite shrub. The aircraft came to rest on its left side, facing the direction of approach, with the tail boom separated from the fuselage. There were no injuries reported.
The investigation
The investigation focused on the flight dynamics during the landing attempt, specifically noting the low main rotor RPM and the loss of anti-torque control effectiveness via the left pedal.