Bell 206B Helicopter Accident at Wonderboom Aerodrome (ZS-HWZ)

Accident Overview and Flight History On 17 February 2021, a Bell 206B helicopter with registration ZS-HWZ was operating a private flight under Part 91 regulations. The aircraft, owned by Moneyflow Sixteen (Pty) Ltd, departed from a farm in the Bela-Bela area at 0415Z with the intention of landing at Wonderboom Aerodrome (FAWB). The pilot-in-command was a 54-year-old male holding a valid Private Pilot Licence with 1,223.1 total flying hours and 1,048.6 hours on type. During the flight, while at approximately 400 feet above ground level in the Pretoria General Flying Area, the pilot experienced an engine in-flight shut-down (IFSD). The pilot reported a tremendous yaw to the right and an engine-out warning. He immediately transmitted a distress call on VHF 124.40 MHz, stating, “HWZ engine failure, going down.” A nearby Robinson R44 pilot relayed the situation to air traffic control at FAWB. ## Forced Landing and Damage The pilot identified a dirt road as a potential landing zone but was unable to complete a successful auto-rotation. The helicopter pitched up significantly, likely due to the main rotor blades impacting a tree on the side of the road. The aircraft came to rest on its skid gear in a nose-down attitude on the side of the road. The helicopter sustained substantial damage, including a severed tail boom and the separation of the main rotor assembly from the drive shaft. The pilot was not injured, and there were no other casualties or damage to property on the ground. ## Probable Cause and Investigation The investigation, led by the South African Civil Aviation Authority’s Accident and Incident Investigations Division, determined that the probable cause was a fracture in the pneumatic Scroll-to-Pc Filter Tube Assembly due to fatigue at the forward Pc filter connection. This failure resulted in the engine in-flight shut-down and the subsequent unsuccessful forced landing on bushy terrain. The report was published on 21 July 2021.