What happened
On 15 April 2016, a Robinson R22 Beta II helicopter, registration ZS-OBJ, was engaged in a game darting operation on a private farm west of Lanseria airport. The flight, involving a commercial pilot and one passenger, was conducting livestock culling activities. While flying at a very low altitude of approximately 10 feet above the ground, the pilot noticed a low rotor RPM warning.
As the aircraft approached a three-meter-high perimeter fence, the pilot attempted an emergency recovery by increasing the throttle and raising the collective. Although the helicopter successfully cleared the fence, the rotor RPM continued to decay, leading to an uncontrolled descent. The aircraft impacted the ground heavily on its skid gear. The impact caused the main rotor blade to sever the tail boom, though the airframe remained upright. The pilot sustained minor head injuries, while the passenger was uninjured.
The investigation
SACAA AIID investigators examined the aircraft's maintenance history, flight logs, and the environmental conditions at the time of the accident. The investigation confirmed that the helicopter had been maintained according to manufacturer schedules and held a valid certificate of airworthiness. Meteorological conditions were clear with good visibility, and the aircraft was operating within its weight and balance limits.
Investigators analyzed the flight mechanics, specifically looking at the potential for a rotor stall. The investigation focused on the operational decisions made during the low-altitude maneuver and the pilot's response to the low RPM warning light and audible alarm.