What happened
On 18 May 1999, a Robinson R44, registration ZS-RHD, was conducting a private flight in the vicinity of Dendron. The pilot was performing an approach to land at a potato factory located on a farm near Dendron, having departed from Farm Kwaggasbult. During the final stages of the approach, at an altitude of roughly 15 feet above the ground, a large industrial bag was displaced by the helicopter's downwash. The bag was blown upward into the path of the main rotor blades.
Following the impact, the pilot successfully executed a forced landing in a nearby open field. There were no injuries reported following the incident.
The investigation
SACAA AIID investigators examined the aircraft following the forced landing. The inspection of the Robinson R44 revealed physical damage to the main rotor blades resulting from the contact with the industrial bag.
Findings
- The primary cause of the incident was the movement of a large industrial bag into the rotor disk.
- The downwash generated by the helicopter's rotors during the landing approach provided the force necessary to lift the bag into the main rotor blades.