What happened
On 31 May 2000, an AS 350 B2, registration ZS-RHW, was conducting a commercial sightseeing flight in the Drakensberg Mountains. The aircraft was operating a domestic charter flight, departing from and intending to return to the Cathedral Peak Hotel. While the pilot and five passengers were flying through a valley at an altitude of approximately 100 feet above the ground, a loud bang was heard originating from the rear passenger area.
Following this sound, the helicopter experienced an immediate left yaw and a simultaneous right roll. The aircraft began shuddering violently, and the flight controls—specifically the cyclic and collective—became heavy, mimicking the sensation of a hydraulic failure. In an attempt to stabilize the aircraft, the pilot lowered the collective to stop the yaw and pulled back on the cyclic to correct the roll. Despite the loss of directional control, the pilot managed to execute a forced landing on an uphill, uneven incline. During the landing, the main rotor blades struck an embankment on the right side, causing the aircraft to overturn 180 degrees. All six occupants successfully disembarked through the front left door without any injuries.
The investigation
SACAA AIID investigators examined the sequence of events following the sudden mechanical disturbance and the subsequent loss of control. The investigation focused on the physical sensations reported by the pilot, specifically the heavy controls and the audible bang, as well as the aircraft's behavior during the low-level flight in the Drakensberg terrain. The inquiry also looked into the lack of visible warning lights or audible warning horns during the incident.