What happened
On 28 February 2018, a Robinson R44 Raven II helicopter, registration ZS-HKZ, was conducting a private flight near the Truter Boerdery farm in Ogies, Mpumalanga. The pilot and one passenger were performing various maneuvers, including hover turns, at an altitude of approximately 100 meters above ground level.
During a steep right-hand turn, a witness on the ground heard a loud bang and a distinct change in engine noise. The tail section of the aircraft separated from the fuselage while in flight. Following the separation, the helicopter entered an uncontrollable spiral, descending in a nose-down attitude. The aircraft crashed near a farm dam, where a post-impact fire erupted and consumed the wreckage. Both occupants sustained fatal injuries.
The investigation
SACAA AIID investigators examined the wreckage and the flight history of the aircraft. The investigation established that the helicopter was operating within its weight and balance limits and that the weather conditions were favorable for flight. The aircraft had previously been involved in a hard landing in 2016, but repairs had been completed according to manufacturer specifications.
Physical evidence from the wreckage, including crushed teeter stops and broken pitch change links, indicated that the aircraft experienced a low rotor RPM condition. The investigation also noted that the pilot was not wearing an approved flying helmet, which may have impacted survivability.