What happened
On 2 December 1999, at approximately 1545 Z, a Piper PA28-181, registration ZS-KWR, was conducting a conversion training flight at Rand Airport. The flight, operated by a training organization, was performing routine maneuvers under favorable weather conditions, with clear skies and a temperature of 22°C. During the third landing attempt on Runway 35, the aircraft unexpectedly veered toward the left side of the runway. The excursion continued onto the grass, where the aircraft swung through a 90-degree angle. There were no fatalities and no injuries reported for the two occupants on board.
The investigation
SACAA AIID investigators examined the wreckage and the mechanical state of the aircraft's landing gear. The investigation focused on the sudden loss of directional control and the physical damage sustained by the airframe during the excursion. The inspection revealed that the lower portion of the left-hand main oleo leg had broken away from the aircraft during the event.
Findings
Technical analysis determined that the primary cause of the excursion was a structural fracture in the left-hand main undercarriage oleo leg outer casting. This failure originated from a fatigue crack located at the undercarriage torque link support bracket. The progression of this crack led to the separation of the main wheel and the oleo leg inner piston from the rest of the landing gear assembly, resulting in the loss of control on the runway.