What happened
On 2 August 2013, a PA-36-285 engaged in agricultural crop spraying operations departed from Jakkalskloof Farm, west of Porterville, in the Western Cape. The pilot, intending to complete a spraying detail on the farm, took off from a gravel runway during a period of strong and variable winds.
Shortly after climbing to approximately 300 feet above mean sea level, the pilot observed a significant increase in wind speed, which made maintaining aircraft control difficult. As the aircraft began to descend, the pilot attempted to recover by increasing engine power and reducing the flap setting to maximize lift. Although the pilot briefly regained control and maneuvered the aircraft toward the right—aiming for the lee side of a hill to find more stable air and avoid obstacles—the aircraft encountered sudden wind shear. Despite an attempt to lighten the aircraft by releasing the intended fertilizer payload, the pilot was unable to overcome the atmospheric disturbance. The aircraft subsequently impacted the ground in a nose-down attitude.
The investigation
The SACAA AIID investigation examined the aircraft's mechanical condition, the pilot's credentials, and the prevailing meteorological environment. The investigation confirmed that the ZS-NOF was airworthy, with a valid Certificate of Airworthiness and maintenance in compliance with regulations. The aircraft's mass and center of gravity were within prescribed limits, and the engine was producing power at the time of impact.
Meteorological data from the South African Weather Services indicated that while the surface wind was light, there had been forecasts for pronounced vertical wind shear between 3,000 and 5,000 feet. The investigation also noted that the pilot was properly licensed with the necessary agricultural and night ratings.
Findings
- The pilot was flying with a valid license and appropriate ratings.
- The aircraft was in a serviceable condition and within weight limitations at the time of departure.
- The pilot experienced a loss of control following an encounter with wind shear.
- The impact resulted in one serious injury to the pilot and substantial damage to the aircraft's forward section, wings, and tail plane.