What happened
On 24 May 2005, a Robinson R22 Beta helicopter, registration ZS-RDO, was engaged in a private operation to count game on a farm near Kakamas in the Northern Cape. The pilot, accompanied by a veterinarian, was monitoring a herd of antelope when he attempted a sharp right-hand turn to follow a Gemsbok that had strayed from the group. During this maneuver, the pilot reported a sudden loss of tail rotor control. As the aircraft began to yaw clockwise, the pilot attempted to correct the movement with the left rudder, but the low rotor RPM warning sounded. The helicopter subsequently performed a hard landing, striking rocky terrain and rolling onto its right side. Both occupants escaped the incident without injury.
The investigation
Investigators examined the wreckage and the mechanical state of the aircraft. Metallurgical analysis of the tail rotor gearbox revealed that the component failed due to an instantaneous brittle fracture caused by impact loading. The examination of the tail rotor blades showed evidence of repeated contact with a solid object. While the pilot initially stated the loss of control occurred at an altitude of 100 to 200 feet, investigators determined the aircraft was actually operating much closer to the ground. The physical evidence, including the location of the tail rotor near the main wreckage, suggested the blades struck an obstacle or the ground itself during the turn.
Findings
- The primary cause of the accident was the tail rotor making contact with an obstacle while maneuvering near the ground.
- The aircraft was not airworthy at the time of the accident, as the mandatory periodic inspection (MPI) had not been performed at the required 100-hour intervals.
- The pilot was operating with an invalid pilot's license, as his medical certificate had expired in April 2005.
- The operation was being conducted without the necessary Domestic Air Services license required for game counting activities.
Safety action
Following the investigation, recommendations were made for the Commissioner for Civil Aviation to improve oversight regarding helicopter game operations. Specifically, the findings highlighted the need to prevent the operation of aircraft without valid licenses or Certificates of Airworthiness, and to ensure that services are not provided without a valid Air Operator’s Certificate. Additionally, a review of regulations regarding livestock and game counting ratings was suggested to ensure alignment with existing air service licenses.