History of Flight
On 2 December 2016 at 1415Z, a Robinson R44 Raven II helicopter (registration ZS-RVY) departed from a private helipad 1 nautical mile northeast of Brits Airfield (FABS) for a scenic flight. The pilot, accompanied by two passengers, intended to land at a private helipad 1 nautical mile northeast of Aviators Paradise (FAAP). While flying along Rooikoppies Dam in the North West Province at approximately 500 feet above ground level, the pilot executed a 180-degree left turn. During the turn, he heard an audible low main rotor RPM warning. The engine instrument indicated a loss of power, and the main rotor RPM gauge showed a decreasing value. The pilot opened the throttle, lowered the collective, and lowered the nose to gain forward speed, but the main rotor RPM dropped to 80%.
Unable to recover, the pilot chose to perform a forced landing into the dam near the riverbed. During the landing, the helicopter flared, and the tail rotor struck the water, causing the helicopter to fall forward. The windshield dislodged, and the helicopter rolled over, sustaining substantial damage. All three occupants emerged without injury. The accident occurred during daylight at coordinates 25°27'35.99"S 027°35'09.11"E, elevation 3326 feet.
Investigation Findings
The helicopter held a valid certificate of airworthiness. The pilot held a valid private pilot license with a helicopter endorsement and a valid medical certificate. He had a total of 295.9 flying hours, with 208.4 hours on the Robinson R44 type. The flight was a private scenic flight operating under Part 91 rules.
The investigation noted that the Robinson Helicopter Company's guidance states that power failure may be indicated by the low RPM horn, and the appropriate response is to lower the collective immediately to enter autorotation. According to the report, the pilot was flying at a height possibly below 500 feet for better viewing, and during a turn with attention diverted, he was surprised by the low RPM horn. The height was insufficient for a successful recovery.
Probable Cause
The probable cause was the helicopter's unsuccessful landing on an unsuitable surface (water) following a loss of main rotor RPM resulting from improper coordination. Additionally, wrong technique during flight and possible distraction were contributing factors.