What happened
On 7 July 2003, a Robinson R-22 Beta helicopter, registration ZS-RBK, was conducting a mountain flying training session near the Magalies Mountain Ridge. The flight, which included a commercial instructor and a student pilot, had been airborne for roughly 40 minutes. After evaluating wind conditions while flying along the ridge, the crew attempted an approach from the west toward a selected landing area.
Following an initial overshoot, the crew attempted a second approach but determined the terrain was too uneven and rocky for a safe landing. In an effort to maneuver the aircraft, the instructor took control and initiated a turn toward the north. During this maneuver, a low rotor RPM warning was triggered. To avoid the more dangerous lee side of the ridge, the crew opted to execute a forced landing. The aircraft's front right skid gear struck the rocky ground at a low forward speed, causing the helicopter to roll onto its left side.
The investigation
Investigators examined the sequence of maneuvers and the mechanical state of the aircraft during the final moments of flight. The investigation confirmed that both occupants were wearing their safety harnesses at the time of impact. While the aircraft sustained substantial damage, there were no fatalities and no serious injuries reported, with the occupants suffering only minor bruising. Following the accident, the occupants contacted the police air wing, which utilized a helicopter to evacuate them from the mountain.
Findings
- The primary cause of the accident was that the pilot exceeded the performance envelope of the Robinson R-22 Beta.
- The aircraft was operated beyond its design limits, creating a situation where the power required for the maneuver surpassed the power available.
- This imbalance led to a critical decay in the main rotor RPM while the aircraft was in close proximity to the ground, making the impact unavoidable.