Robinson R44 Raven II Accident at Lawley, South Africa (ZS-RMN)

Accident Overview and Flight History On 25 September 2009 at approximately 2100Z, a Robinson R44 Raven II helicopter, registration ZS-RMN, was conducting a commercial vehicle tracking operation in the Lawley area, south of Soweto, Gauteng, South Africa. The aircraft was operated by National Airways Corporation (PTY) LTD and carried a pilot and one passenger, an air tracker. The flight departed from Rand Aerodrome (FAGM) with Grand Central Aerodrome (FAGC) as the intended destination. During the operation, the pilot overflew Lawley for approximately 19 minutes at 6,400 feet AMSL. The pilot observed the throttle beginning to hunt, described as an opening and closing movement. While in a 15-degree left turn, both the pilot and passenger heard a change in engine pitch. The pilot then observed that both the engine and rotor RPM needles had moved to the top of the gauge, indicating an overspeed condition. ## Emergency Response and Impact The pilot levelled the helicopter, closed the throttle, and lowered the collective pitch lever slightly in an attempt to reduce the RPM. When the overspeed condition remained unresolved, the pilot entered autorotation and selected a landing zone. The helicopter flared close to the ground, resulting in a hard landing. The aircraft remained on its skids, but the impact caused the main rotor blades to sever the tail boom from the fuselage. The helicopter sustained substantial damage. Neither the pilot nor the passenger was injured, and both evacuated the aircraft unassisted. The accident site was located in an open grass-covered field next to Lawley Township, with GPS coordinates S 26° 23' 54