What happened
On the morning of February 3, 2001, a Robinson R-22 Beta, registration ZS-RBK, was conducting a private scenic flight near Wakkerstroom Aerodrome. After an initial solo flight, the pilot returned to the aerodrome to pick up a passenger and embarked on a second flight along the same route.
During the return to the aerodrome, the pilot noted an unusual engine sound while hovering approximately 10 feet above the ground. Although the engine and rotor RPM indicators showed only marginal underperformance, the pilot elected to perform another circuit before attempting a final landing. During the subsequent approach down runway 22, the aircraft's low RPM indicator activated at 35 feet above ground level. As the helicopter continued to lose both engine and rotor power, it lost altitude while maintaining a forward speed of approximately 40 knots.
Realizing a crash was imminent, the pilot attempted a controlled slide landing on the long grass terrain. The impact caused the aircraft to roll over, leaving the passenger suspended by their seatbelt. There were no injuries reported following the incident.
The investigation
The investigation focused on the sequence of power loss and the pilot's decision-making process following the initial detection of engine irregularities. Investigators examined the aircraft's performance during the low hover and the subsequent approach, noting that while instruments initially appeared within normal limits, the power loss became critical during the final descent.
Findings
- The primary cause of the accident was a loss of engine power, which prevented the aircraft from maintaining altitude.
- A significant contributing factor was the pilot's decision to continue flight operations and execute an additional circuit despite observing signs of engine underperformance during the initial hover.