On October 8, 1998, approximately 1730 central daylight time, an Air Tractor AT-502B agricultural airplane, N502S, registered to a private individual and operated by Superior Ag-Air of Byers, Texas, collided with a power line while maneuvering near Ringling, Oklahoma. The airplane sustained substantial damage, and the commercial pilot, sole occupant of the aircraft, was not injured. Visual meteorological conditions prevailed and no flight plan was filed for the Title 14 CFR Part 137 aerial application flight. The flight originated from the Perry Municipal Airport, Perry, Oklahoma, approximately 1615, and the intended destination was Byers. The pilot reported that he was spraying a 20 acre wheat field with a double pole power line crossing the middle of the field. As he made a pass toward the west, the sun "obstructed" his vision, and he collided with a pair of poles and wires of the power line. The pilot landed the airplane in a pasture approximately one mile north of the field. Examination of the airplane by an FAA inspector revealed that there was a hole in the upper left side of the fuselage, the inboard portion of the left flap was bent upward, the left spray boom was partially separated, and the upper half of the rudder was torn off. The inspector located the separated portion of the rudder in the field that the airplane had been spraying. He reported that a power line ran diagonally across the north part of the field from northwest to southeast and was supported by pairs of poles approximately 60 feet tall. The upper crosspiece was separated from one pair of poles and lying on the power transmission wires, and the upper static wire was severed.