What happened
On August 27, 2000, at approximately 11:00Z, an Enstrom helicopter, registration ZS-HNA, was conducting a private flight from Phalaborwa to Pietersburg. During the flight, the pilot diverted the aircraft to visit friends at the Sondela Game Reserve near Warmbaths.
While attempting to land at the reserve, the pilot encountered difficulties during the approach. Under favorable weather conditions with winds of approximately 10 knots, the pilot miscalculated the wind speed and direction. As the aircraft entered a hover, it drifted forward toward a group of trees. During this maneuver, the pilot failed to maintain sufficient engine power, leading to a critical drop in rotor RPM.
The investigation
SACAA AIID examined the circumstances surrounding the impact. The investigation established that the aircraft, operated by Plastic Pack (Pty) Ltd, was carrying two occupants at the time of the incident. There were 0 fatalities and 0 injuries resulting from the event. The investigation focused on the pilot's handling of the aircraft during the transition to a hover and the subsequent mechanical state of the rotor system.
Findings
- The pilot misjudged the prevailing wind speed and direction during the landing approach.
- The aircraft drifted toward nearby vegetation during the hover phase.
- The pilot allowed the main rotor RPM to decay to a level that rendered the helicopter uncontrollable, resulting in the main rotor blades striking a tree.