What happened
On the afternoon of 23 November 2023, a Robinson R44, Raven II helicopter, registered ZS-PSZ, departed from the Ultimate Heli facility in Midrand for a private flight. The aircraft, operated by Ultimate Heli (Pty) Ltd, was being flown by two pilots under visual meteorological conditions. After taking off at 1400Z, the helicopter climbed to 6,000 feet above mean sea level and maintained contact with air traffic control at Grand Central Aerodrome.
Approximately 39 minutes into the flight, while returning to the departure point and flying near a quarry roughly 3.92 nautical miles south of FAGC, the aircraft suffered an engine failure. The helicopter lost altitude and struck the ground hard on its skids. The impact was severe enough to destroy the aircraft and caused one main rotor blade to sever the tail boom. Both occupants sustained serious injuries and required medical evacuation to a Johannesburg hospital.
The investigation
The SACAA AIID investigation examined the wreckage and flight history of the aircraft. Investigators found that the helicopter had undergone a 100-hour mandatory periodic inspection just 16.1 airframe hours prior to the accident. The engine and main transmission remained attached to the airframe following the impact, and the fuel tanks were found to be intact with sufficient Avgas 100LL remaining.
Analysis of the cockpit revealed that the rotor brake was in the pulled position and the throttle was near idle. Evidence from the engine cooling fan suggested the engine was producing little to no power at the moment of impact. The investigation also noted that the aircraft was not equipped with flight data or cockpit voice recorders.