What happened
On the morning of 6 December 1999, a Piper PA31-350, registration ZS-OJY, departed Rand Airport on an international charter flight destined for Oranjemund, Namibia. The flight was part of a regular service transporting personnel between Johannesburg and Namibia.
Shortly after the aircraft became airborne, the pilot reported a mechanical issue involving an engine defect. Within approximately two minutes of takeoff, the aircraft lost altitude and crashed near the extended centerline of Runway 29, roughly two nautical miles west of the airport. The impact was followed by a post-crash fire that completely destroyed the aircraft. The pilot and all nine passengers on board were killed in the accident.
The investigation
SACAA AIID investigators examined the mechanical state of the aircraft and the operational procedures of the charter operator. The inquiry focused on the condition of the right-hand engine and the weight of the aircraft at the time of departure.
Technical analysis of the wreckage and maintenance records revealed that the right-hand engine had suffered a loss of power. Furthermore, the investigation scrutinized the aircraft's weight and balance. Investigators compared the actual weight of the passengers and baggage against the aircraft's certified limits. The investigation also reviewed maintenance logs, noting discrepancies in how airframe hours were recorded and identifying that the aircraft had exceeded its scheduled mandatory periodic inspection interval.
Findings
- The primary trigger for the accident was a mechanical failure of an exhaust pipe segment, which caused the right-hand engine to lose power.
- The aircraft was overloaded, and in this heavy configuration, it lacked the performance capability to maintain a safe climb on a single engine.
- There were discrepancies in the maintenance tracking, as the aircraft had flown beyond its permitted interval for a mandatory periodic inspection.
- Inconsistencies were noted in the documentation regarding the aircraft's maximum ramp weight and the impact of installed vortex generator kits on performance calculations.