Hughes 369HS Tail Rotor Failure During Netstar Operation in Cape Town (ZS-HFE)

Accident Overview and Operation Details On 11 August 2000 at 1140Z, a Hughes 369HS helicopter, registration ZS-HFE, was conducting a commercial Netstar operation near Cape Town, South Africa. The aircraft departed from Cape Town International Airport (FACT) and was returning to the same location. The pilot-in-command held a commercial licence and had 1,946.5 total flying hours, including 209.0 hours on type. The flight carried the pilot and two passengers, one of whom was a Netstar observer. ## Sequence of Events Approximately 1.2 hours after takeoff, the pilot was orbiting a suspect vehicle at about 1,300 feet AGL when high-frequency vibration was felt through the directional control pedals. The pilot initiated an autorotational descent. The vibration continued through the airframe and tail rotor. At around 150 feet AGL, the pilot reported that the tail rotor system separated from the aircraft and contacted the main rotor blades. ## Forced Landing The helicopter became difficult to control, with a tendency to dip to the right. At approximately 50 feet AGL, the pilot decelerated and applied collective to cushion the landing. The aircraft entered a right-hand spin, yawing about 90 degrees before the pilot retarded the throttle to idle. It completed a full 360-degree yaw to the right and touched down in a 30-degree right roll attitude. On ground contact, the aircraft yawed an additional 90 degrees to the right as the skid gear assembly collapsed, causing the helicopter to roll onto its right side. ## Injuries and Location The accident occurred at a sports field near Secondary School Groenvlei in Lansdowne, Cape Town. The pilot sustained a cut to his right hand; no other occupants were injured. No fatalities were reported. ## Probable Cause The investigation concluded that an undetermined precipitating event on the missing half of the tail rotor blade caused an imbalance that overloaded the failed fork bore, liberating one side of the fork bolt. The fork bolt then bent and twisted to failure. The pitch change links failed as the tail rotor left the helicopter. The resulting instability necessitated a forced landing and prevented a successful autorotation, leading to a hard landing on the right skid, which collapsed before the helicopter rolled onto its right side.