Overview
An aircraft conducting an aerial application mission collided with the ground while attempting to abort the operation due to weather conditions. The pilot was spraying a field when flagmen and farmers signaled him to leave because of an approaching thunderstorm. During the subsequent turn, the aircraft encountered wind shear, which forced the right wing downward and led to impact.
Sequence of Events
The pilot stated that he had made two passes over the field when he noticed the flagman and farmers waving him off due to an approaching thunderstorm. After deciding he was supposed to leave, the pilot initiated a standard right turn to the north. He then encountered wind shear, which forced the right wing down almost to an inverted position before it contacted the ground. According to witnesses, after circling to confirm the signal to leave, the aircraft began a right turn, lost altitude rapidly, and struck the ground right wing first.
Weather Conditions
Weather observations from Yuma, Arizona, at 1055 hours listed cumulonimbus clouds moving from southeast to northwest through the northwest quadrant in the remarks section. The pilot reported turbulent air and wind shear during the maneuver.