Accident Details
On 3 February 2001 at 0530Z, a Robinson R-22 Beta helicopter, registration ZS-RBK, was involved in an accident at Wakkerstroom Aerodrome. The pilot, holding a private license, had logged 216.7 total flying hours, with 175.6 hours on the R-22 type. The operation was a private flight. The weather was fine with a temperature of 17°C, dew point 13°C, humidity 81%, and no wind. The helicopter departed with the pilot solo for a scenic flight, returning after 20 minutes. A passenger then boarded, and the same route was flown again.
Flight Sequence
Upon returning to the aerodrome, the pilot positioned the helicopter in a low hover at approximately 10 feet above ground level. The pilot reported not being entirely satisfied with the sound of the engine, though the engine and rotor rpm indicators showed only marginal underperformance. The pilot decided to perform another circuit and then come in for a final landing. During the subsequent flight down runway 22, the instruments indicated operation at the top of the green arc, and the transition was completed without issue. However, at 35 feet AGL, the low rpm warning indicator activated as the aircraft continued to lose power, with both engine and rotor rpm indicators declining.
The helicopter began losing altitude, while forward speed was maintained at approximately 40 knots. Recognizing that ground impact was unavoidable, the pilot initiated a slide-on landing. The terrain was described as fairly level with a slight downslope to the right, covered in long grass. According to the pilot, the helicopter rolled over during the impact, resulting in the passenger hanging from the seatbelt above the pilot. No injuries were reported among the two occupants.
Probable Cause
The probable cause of the accident was an engine power loss that rendered the aircraft unable to gain height, leading to a forced landing. Additionally, the pilot's decision to execute another circuit while aware that the engine was not delivering full power was considered a significant contributing factor.