On September 3, 1999, at 1545 central daylight time, a Grumman-Schweizer G-164A agricultural airplane, N7362, was destroyed following impact with powerlines while maneuvering during an aerial application flight near Seminole, Texas. The instrument rated commercial pilot, sole occupant of the airplane, sustained minor injuries. The airplane was registered to Hatfield Spraying Service , Inc., of Nunica, Michigan, and operated by J.R. Davis Flying Service, of Seminole, Texas. Visual meteorological conditions prevailed for the Title 14 CFR Part 137 aerial application flight for which a flight plan was not filed. The flight originated from a private airstrip near Seagraves, Texas, at approximately 1535. The pilot reported to the FAA inspector, who responded to the accident site, that the purpose of the flight was to dispense chemicals on a section of land west of Seminole, as part of the boll weevil eradication program. During the 12th application pass, while approaching the field on a southerly heading, the airplane collided with the two top guide wires of a power transmission line running in a east-west direction. The pilot stated that he was aware of the presence of the unmarked powerlines. He added that there were a total of 8 cables suspended between the towers. The top two wires, which were suspended approximately 80 to 90 feet above the ground, were much thinner and not as dark as the other 6 cables. The pilot further reported that following the impact with the guide wires, the airplane spun to the right and impacted the ground inverted. The pilot, who was wearing a flight helmet with a visor, exited the airplane on his own. A post-impact fire destroyed the radial engine powered biplane. In a telephone interview with the NTSB investigator-in-charge, the pilot reported that the airplane's windscreen was clear and clean. He stated that he was wearing his eyeglasses under the visor. He also told the IIC that he had flown 100 to 120 hours in the preceding 2 weeks; however, he did not feel tired or fatigued. The pilot admitted that his attention was diverted to the light bar for the SatLoc swath guidance system installed in the airplane.