What happened
On 1 February 2025, a Robinson R44 Raven II helicopter, registration ZS-RUT, departed Rand Airport (FAGM) in Gauteng for a private flight to the Kromvlei Helicopter General Flying Area (GFA). The flight, operated under Part 91 regulations, included the pilot and two passengers.
Upon arriving at the Kromvlei GFA, the pilot observed another helicopter on the circuit for Runway 35 and elected to follow behind it. During the final approach, as the pilot attempted to flare the aircraft for landing, the main rotor RPM began to decrease. In an attempt to recover, the pilot applied maximum power and excessive left pedal; however, the RPM continued to drop below 97%. This loss of power caused the helicopter to swing 270 degrees to the right, leading to a loss of control and a hard impact on the right side of the runway. There were 0 fatalities and 0 injuries, though the aircraft sustained substantial damage to the tail boom, tail rotor, and skid landing gear.
The investigation
The SACAA AIID investigation confirmed that the pilot was properly licensed and medically fit for the flight. Pre-flight inspections had been completed with no anomalies noted, and the aircraft's mass and balance were within permissible limits. The investigation also verified that the Robinson R44 Raven II had a valid Certificate of Airworthiness and had been maintained by an approved organization.
Findings
- The pilot experienced a decay in main rotor RPM below the 97% threshold during the landing flare.
- A tailwind of approximately 5.6 knots was present on Runway 35 at the time of the accident.
- The primary cause of the accident was the loss of control resulting from low main rotor RPM during the flare.
- Poor landing technique was identified as a contributing factor.