History of Flight
On 19 September 2012, at approximately 0913Z, a Robinson R44 Raven II helicopter (registration ZS-HGG) departed Rand Airport (FAGM) on a scenic flight to the Johannesburg central business district. The pilot, a commercial pilot with 569.6 total flying hours (232.7 on type), was accompanied by two passengers. After take-off, the pilot executed a 180-degree left turn over a golf course and the PPC cement factory. During a second left turn at about 300 ft above ground level, the pilot heard a high-pitched noise and observed an increase in engine RPM, with the engine tachometer needle moving off-scale. The pilot immediately rolled off the throttle. Subsequently, both engine and main rotor RPM decayed rapidly, and the low main rotor warning horn activated. The pilot lowered the collective to enter autorotation and attempted to flare. The helicopter made a hard landing on an old construction site in Germiston, breaking off its skids and rolling onto its left side.
Injuries
The pilot and one passenger sustained minor injuries. The second passenger sustained serious injuries and was admitted to hospital.
Damage to Aircraft
The helicopter sustained substantial damage during the impact sequence.
Meteorological Information
Weather conditions at the time were fine: wind 240° at 7 knots, temperature 24°C, visibility CAVOK, sky clear.
Probable Cause
The investigation determined the probable cause to be an unsuccessful forced landing following a decay in main rotor RPM in flight.