History of Flight
On 5 August 2010 at approximately 16:00Z, the pilot, who was also the owner of the helicopter, departed from Klein Zwart Bast Farm in the Northern Cape with a passenger on a repositioning game culling flight to Groot Riet Farm. The helicopter did not arrive at its destination at the expected time. The South African Police Service (SAPS) and local farmers initiated a search along the planned flight path. The wreckage was located the following morning, 6 August 2010, at approximately 08:10Z.
The accident site was an open, deserted landscape at GPS coordinates S29°24.572 E020°43.265, approximately 3.7 nautical miles north of Groot Riet Farm. The aircraft was destroyed on impact, and both occupants were fatally injured.
Investigation Findings
On-site investigation revealed that wiring for the navigation lights and strobe light inside the tail boom had become wrapped around the tail rotor drive shaft and stacked up against the flex plate assembly at the tail rotor gearbox end. It is likely that the pilot experienced vibration and noise from this condition and decided to land as soon as possible.
GPS data indicated the accident occurred at approximately 16:08Z, after sunset and when the sun had disappeared below the horizon, resulting in a lack of visual reference. The helicopter sustained a hard landing on its main landing skids during a vertical descent. The helicopter remained upright but was destroyed upon impact with the level, bush-covered terrain. The engine was not running at the time of impact, as evidenced by the stationary squirrel cage fan. The collective stick was in the fully up position, suggesting an attempt to cushion the landing just before impact.
Probable Cause
The probable cause of the accident was an unsuccessful autorotational landing. A contributory factor was the pilot becoming disorientated due to reduced visibility conditions after sunset.