What happened
On 28 September 2017, a Robinson R44 Raven II helicopter, registration ZS-OSL, crashed in the Lwandle area near Somerset West. The flight originated from Cape Town International Airport, with the pilot intending to fly to Struisbaai for a private visit. The aircraft was operating under Part 91 regulations and had been rented for the day following a successful proficiency check two days prior.
During the return leg of the flight, witnesses at Nomzamo High School observed the helicopter orbiting the area. Shortly thereafter, the aircraft was seen in a steep, nose-down attitude. As the helicopter descended, it struck electrical cables running along the school's perimeter fence, causing visible sparks, before impacting the school yard. The impact was severe, causing the aircraft to disintegrate into multiple pieces. The pilot sustained fatal injuries, while no other persons were on board or injured.
The investigation
SACAA AIID investigators examined the wreckage, engine components, and surveillance footage from the N2 highway. The investigation confirmed that the Robinson R44 Raven II was airworthy, properly maintained, and within weight and balance limits at the time of departure. The engine was found to have been operating normally prior to the impact, and no mechanical failures were identified during the teardown of the Lycoming engine.
Analysis of surveillance video showed the aircraft transitioning from a banking left turn into an increasingly steep descent. The investigation also noted that the aircraft was under power when it severed the electrical cables. There was no evidence of pre- or post-impact fire, and the aircraft still contained usable fuel at the time of the crash.