A September 2014 undershoot accident involving a Pilatus PC-12 that encountered wind shear while trying to land at Coober Pedy, South Australia, offers a reminder to pilots of the hazards surrounding the phenomenon, according to the final report on the accident released last week by the Australian Transport Safety Bureau.
Approaching the airport vicinity, the pilot saw a line of storm activity, virga and blowing dust. The pilot discontinued the first approach to Runway 32 after losing visual contact in blowing dust. As the aircraft descended through about 100 feet agl during the second attempt, the pilot encountered strong wind shear and noted a significant increase in the aircraft’s sink rate. Almost simultaneously, the aircraft was again engulfed in blowing dust that deprived the pilot of any external reference.
He contemplated a second go-around, but after noting the high sink rate, the intensity of the turbulence and the proximity of the aircraft to the ground, he realized the maneuver would not be successful.
The aircraft touched down on a firm surface short of the runway threshold, tore through a wire perimeter fence and stopped after a 500-foot ground roll. Neither the pilot nor the lone passenger was hurt.