What happened
On 17 September 2015, a Robinson R44 was conducting an aerial livestock inspection at Hillcrest Game Farm in the North West Province. Following a refueling operation, the pilot attempted to lift off from the site. During the initial transition to flight, the helicopter experienced an uncommanded yaw to the right.
As the aircraft moved, the front tip of the right skid made contact with a refueling bowser that had been left approximately 3 meters from the takeoff point. The skid became hooked onto the bowser's frame, creating a pivot point. This contact triggered a dynamic rollover, causing the aircraft to tilt and the main rotor blades to strike the ground. The impact was severe enough to fracture the right skid, eventually releasing the aircraft, but the subsequent uncontrolled movement caused the tail boom and tail rotor assembly to strike the earth, resulting in significant structural damage.
The investigation
SACAA AIID investigators examined the wreckage and the operational circumstances surrounding the takeoff. The investigation focused on the proximity of the refueling equipment to the aircraft's rotor radius. The investigators noted that the Robinson R44 has a main rotor diameter of approximately 10.2 meters, meaning any obstacle should ideally be positioned at least one meter beyond the blade tips to ensure safe clearance.
Technical analysis of the wreckage confirmed that the damage to the tail rotor gearbox and tail boom was consistent with high-energy contact with the ground while the blades were rotating. The investigation also reviewed maintenance records, which showed the aircraft had been properly maintained and was airworthy at the time of the incident.
Findings
- The refueling bowser was not moved to a safe distance prior to the takeoff attempt.
- The helicopter's right skid became entangled with the bowser, which acted as a pivot point for the aircraft.
- The collision induced a dynamic rollover that the pilot was unable to recover from due to the low altitude.
- The pilot failed to follow standard safety procedures regarding obstacle clearance during the lift-off transition.