On May 10, 1995, at 1100 central daylight time, a Cessna 177B, N34628, was substantially damaged during approach near Casa, Arkansas. The commercial pilot was seriously injured. The airplane departed Russellville, Arkansas, at 1040 CDT for the personal flight conducted under Title 14 CFR Part 91. No flight plan was filed and visual meteorological conditions prevailed. The pilot stated that he was familiar with the private airstrip and "well aware" of the high voltage transmission line which is located 850 feet south of the approach end of runway 33 and runs from east to west. He further stated that he was on final approach to land on runway 33 when he "saw too late the smaller shield wires on top of the transmission lines." At approximately 120 feet above ground level, the airplane's landing gear contacted one of these two upper non-current carrying wires. The airplane then fell to the ground coming to rest inverted. There were no aerial marking balls installed on the transmission line.