What happened
On 2 March 2000, a Mooney aircraft, registration ZS-LGU, was conducting a private flight from Welkom to Welbedacht Aerodrome. While attempting to land on Runway 21, the pilot was operating with full flaps at an indicated airspeed of 80 knots. During the approach, the aircraft encountered sudden gusty conditions and a significant wind shear. This atmospheric disturbance caused the right-hand wing to lift abruptly.
Although the pilot managed to regain control of the aircraft, the landing was heavy. The momentum caused the aircraft to balloon and subsequently roll through a trench located at the end of the runway, eventually breaching the boundary fence. The impact resulted in the collapse of the undercarriage and caused damage to the propeller and the wing covering.
The investigation
The investigation focused on the flight conditions and the sequence of events leading to the excursion. Meteorological data provided by the pilot indicated that winds were varying between 01 and 10 degrees, with a surface temperature of approximately 19°C. The investigation confirmed that there were no injuries to the pilot or the two passengers on board.
Findings
- The primary factor in the accident was the occurrence of wind shear and sudden changes in wind direction/speed during the landing phase.
- The aircraft's heavy landing and subsequent roll were direct consequences of the aerodynamic instability caused by the gusts.
- The structural damage to the Mooney was a result of the aircraft exiting the runway environment and striking the trench and perimeter fencing.