On August 4, 2005, at 0740 central daylight time, a Grumman G-164A, N6858Q, was destroyed by post impact fire after the airplane hit a power line and impacted the terrain near Buchanan, North Dakota. The commercial pilot received serious injuries. The Title 14 Code of Federal Regulations Part 137 aerial application flight departed from a private airstrip at 0700 on a local flight. Visual meteorological conditions prevailed. No flight plan was filed. The pilot reported that he had sprayed one cornfield and was starting to spray another 20-acre cornfield. He reported that he flew over the field and observed power lines. He reported that he had sprayed the same cornfield the year before and had flown under the power lines without incident. He made one pass flying east, and then another pass flying west. He reported that during the third pass flying to the east, the airplane struck the wires. He reported his vision was obstructed by glare on the windshield. The airplane impacted the ground and caught on fire. The pilot was able to exit the airplane before it was consumed by fire. The pilot indicated that there were no mechanical malfunctions of the airplane prior to the impact with the wires.