What happened
On 28 December 2009, a Beech Bonanza F33A, registration ZS-NAF, departed Vereeniging Aerodrome for a private flight to Margate Aerodrome. The flight was conducted under instrument flight rules (IFR). While en route, the pilot contacted Johannesburg East air traffic control to report an electrical malfunction and expressed the intention to divert to Harrism and Aerodrome.
During the period following the request to divert, the aircraft disappeared from radar. The wreckage was subsequently located on Platberg Mountain at an elevation of 6,194 feet. The impact was severe, resulting in the destruction of the aircraft and the deaths of all four occupants.
The investigation
Investigators examined the wreckage and flight communications to reconstruct the final moments of the flight. Analysis of the propeller indicated that the engine was still operational at the moment of impact. However, the investigation could not definitively identify the source of the reported electrical issue, as the alternator was not recovered from the crash site.
Meteorological data confirmed that instrument meteorological conditions (IMC) were present, characterized by low visibility, mist, and broken cloud layers. The investigation also noted that the pilot's reliance on the autopilot likely increased the complexity of the situation once the electrical failure necessitated manual flight in adverse weather.
Findings
- The pilot was properly licensed, rated, and medically cleared for the flight.
- The aircraft was maintained according to regulatory standards.
- Severe weather, including fog and low cloud ceilings, prevailed over the accident site.
- The pilot reported an electrical failure prior to the accident.
- The primary cause of the accident was controlled flight into terrain during instrument meteorological conditions.
- Contributing factors included an undetermined electrical malfunction and a subsequent loss of situational awareness.