Air Tractor AT502 crop dusterAT 502 Crop Duster airplane model. The prototype AT 502 (N7314D) was first flown in April 1987, and this model entered service in February 1988. The first examples in this region commenced work on cotton spraying during that year. The power plant was the 507 kw (680 shp) PT6A 15AG turbine, but the airframe was certified for the installation of the 559 kw (750 shp) PT6A 34AG if required. The AT 502A, which was first flown in January 1992, had the 821