What happened
On 2 October 2012, a Robinson R44 helicopter, registration ZS-RNI, was engaged in a game counting operation near Farm Grootfontein in the Bela Bela district of Limpopo province. The aircraft, carrying a pilot and three passengers, departed from an open area on the farm to perform low-level observations. During the flight, the crew encountered a herd of Impala antelope that remained stationary beneath a group of trees.
While flying at an altitude of roughly 100 feet above ground level and maintaining an airspeed of 15 to 20 knots, the pilot attempted to disperse the animals by diving toward them after several orbits. During this maneuver, the aircraft encountered erratic wind conditions, likely placing the helicopter in a downwind position. This resulted in a decay in main rotor RPM, triggering both the visual and audio warnings on the instrument panel. Due to the low altitude, the pilot could not recover the necessary RPM and was forced to perform an emergency landing in dense bush terrain. Upon impact, the main rotor blades struck the tail boom, causing the aircraft to roll onto its right side. There were 0 fatalities and 0 injuries reported.
The investigation
SACAA AIID investigators examined the circumstances surrounding the flight, noting that the operation was being conducted with all four doors removed from the aircraft. The investigation focused on the aerodynamic changes during the low-level maneuver and the impact of shifting wind velocities on the helicopter's stability and power management. The investigation also considered the pilot's decision to descend toward the wildlife as a primary factor in the loss of rotor speed.