What happened
On 4 August 1999, a Robinson R22, registration ZS-HXO, was engaged in a private game capturing operation at the Wonderkop Nature Reserve. During the exercise, after securing zebras within a boma, the pilot attempted to maneuver the aircraft. While applying power, the pilot believed the aircraft had sufficient clearance from nearby vegetation; however, the tail rotor made contact with a tree.
Following the impact, the pilot immediately reduced the throttle and lowered the collective pitch. Despite these actions, the aircraft became uncontrollable and subsequently crashed sideways into another tree located approximately 30 metres from the initial point of impact.
The investigation
The investigation focused on the sequence of events during the low-level maneuvering required for the game capture task. Investigators examined the aircraft's flight path and the mechanical consequences of the initial impact. It was established that the contact between the tail rotor/stabilizer assembly and the tree caused these components to separate from the tail boom, leading to the loss of directional control.
Findings
- The pilot was operating at a low altitude relative to the surrounding trees during the operation.
- The tail rotor and stabilizer assembly struck a tree, causing structural separation from the tail boom.
- The resulting loss of control led to the secondary impact with a second tree.
- The pilot sustained a broken third vertebra and required emergency medical evacuation to Unitas Hospital in Pretoria.