Accident Details
On 8 November 1999 at 1300Z, a Hughes 269C helicopter, registration ZS-HFB, was conducting a survey flight in the lower Drakensberg, between Mount Fletcher and Matatiele. The pilot held a private pilot licence with 115.0 total flying hours and 94.4 hours on type. The helicopter departed from and was destined to return to the Matatiele area.
Meteorological Conditions
Weather at the time was fine, with wind from 110° at 25 knots.
Sequence of Events
According to the pilot, while ascending a valley, the helicopter encountered a sudden and severe downdraft. In an attempt to escape the downdraft, the helicopter was forced into the side of the mountain. It landed heavily on sloping terrain and then rolled over the edge of a 4–5 metre cliff, coming to rest inverted. The pilot freed himself and then assisted the passenger. As they moved away from the wreckage, a fire broke out. The pilot attempted to extinguish the fire but was unsuccessful, and the wreckage was destroyed.
A statement from the passenger corroborated the pilot's account. The passenger reported that at approximately 1300Z, they were climbing in a valley when they suddenly encountered severe turbulence. The pilot tried to manoeuvre out of the valley, but the aircraft was forced into the mountain side. The passenger then recalls being released from the seat belt by the pilot and running away from the aircraft, after which the fire occurred.
Injuries and Damage
One person was injured. No persons were killed. The helicopter was destroyed by fire.
Probable Cause
While ascending a valley the pilot encountered a sudden and severe downdraught. He was unable to escape from the condition and the helicopter was forced into the side of the mountain, it landed heavily and rolled over.