What happened
On 17 February 2015, a Robinson R44 helicopter, registration ZS-RNF, was involved in an accident on a private farm near the Port Elizabeth region. The pilot was conducting a commercial operation to transport a bontebok, a medium-sized antelope, from the farm to Humansdorp.
During the attempt to lift off from the rocky terrain, the helicopter experienced a sudden roll. The pilot reported that the right landing skid appeared to become caught on a rock during the ascent. This triggered a dynamic rollover, causing the aircraft to impact the ground in a nose-down attitude. Although the pilot and two passengers managed to evacuate the wreckage before a post-impact fire consumed the airframe, no injuries were sustained by the occupants.
The investigation
SACAA AIID investigators examined the aircraft's weight and balance, the loading configuration, and the mechanical state of the helicopter. The investigation established that while the total weight of the aircraft remained within the maximum allowable takeoff limits, the distribution of that weight was critically flawed.
The pilot had performed mass and balance calculations for the initial flight from Port Elizabeth; however, these calculations did not account for the weight of the animal being transported. To compensate for the heavy cargo placed on the right-hand skid, the pilot had to use left-hand cyclic control to maintain level flight. The investigation also noted that the terrain, characterized by rocks and bushes, contributed to the skid catching an object during the power application.
Findings
- The primary cause of the accident was a dynamic rollover occurring during the takeoff phase.
- The aircraft was heavily unbalanced, with the center of gravity shifted significantly toward the right-hand side due to the placement of the cargo on the skid.
- The pilot failed to perform a new mass and balance calculation to include the weight of the animal for the specific cargo-moving leg of the flight.
- The weight distribution was incorrect, placing the center of gravity over the right skid.
- The accident was not part of the original flight plan, and the pilot assumed sufficient fuel reserves and weight margins existed without formal verification.