On August 5, 1995, at 0805 central daylight time (cdt), an Schweizer G-164A, N7994, was substantially damaged when it struck transmission wires while maneuvering during an aerial application. The pilot reported minor injuries. The local 14 CFR Part 137 flight departed a private airstrip in Grand Forks, North Dakota, at 0740 cdt in visual meteorological conditions. No flight plan was on file. The pilot reported he was in the process of spraying a field which had powerlines located along the east perimeter of the field and another set of powerlines which ran from the northwest to the southeast over the field. While finishing his fourth pass over the field, the pilot stated "I was going under the powerline in the field and over the small one by the road. The sun was very low in the east causing some visual problem and maybe made me misjudge the location of the powerlines." The airplane struck the powerline, yawed to the right, and impacted the ground.