What happened
On 19 October 2022, a Robinson R22 Beta helicopter, registration ZS-RBM, was engaged in a game capture operation at the Ozabeni Game Reserve in KwaZulu-Natal. The flight was being conducted under visual meteorological conditions as part of a Part 137 operation.
During the mission, the pilot had removed the helicopter doors to facilitate the operation. When rain began to fall, the pilot landed the aircraft with the intention of retrieving the doors, which were positioned approximately 8 metres ahead of the landing site. After landing, the pilot lowered the collective, moved the throttle to the off position, and applied friction to the controls while the engine remained at idle.
Upon disembarking to retrieve the doors, the pilot noticed the engine RPM increasing. The aircraft's nose lifted, causing the tail stinger to touch the ground, and the helicopter became airborne. The aircraft drifted backward roughly 15 metres while yawing to the right. The flight ended when the main rotor blades struck the ground, causing the fuselage to settle on its starboard side. The pilot, who was at a distance from the aircraft during the movement, was not injured, though the helicopter suffered substantial damage to its blades, fuselage, tailboom, and skids.
The investigation
SACAA AIID examined the operational and maintenance status of the aircraft and the pilot's credentials. The investigation confirmed that the pilot held a valid Commercial Pilot Licence with the necessary type and culling ratings. The aircraft's Certificate of Airworthiness was valid, and a mandatory periodic inspection had been completed recently in September 2022. The operator also held a valid Air Operating Certificate with the appropriate endorsements for game culling and herding.
Findings
- The primary cause of the accident was that the helicopter was left unattended while the engine and rotors were still running.
- This resulted in an uncommanded takeoff and subsequent ground impact.
- Deteriorating weather conditions, specifically the onset of rain, acted as a contributing factor to the sequence of events.