On August 12, 2012, about 2030 eastern daylight time, an experimental amateur-built Dykas Kitfox Series 7, N646FD, struck a power line during final approach to a private grass airstrip near Monroe, Michigan. The private pilot sustained serious injuries and a passenger sustained minor injuries. The airplane sustained substantial damage to the fuselage. The airplane was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed and a flight plan had not been filed for the local flight that departed from the airstrip at 2015. The pilot stated that he took a family member for an airplane ride over his house. They circled over the house and returned to the departure airstrip. During the approach to the airstrip, the pilot thought he was high enough to clear the power line that was along the approach. The right main landing gear wheel contacted the power line, and the airplane descended and impacted the ground. The pilot stated that the accident could have been prevented by "giving more attention to the location of the wires and staying a little higher so [he] would be plenty high to clear them." The pilot stated that there was no mechanical malfunction/failure with the airplane at the time of the accident. According to a Federal Aviation Administration (FAA) inspector, the pilot was operating under a sport pilot certificate because his medical certificate, last issued in 2009, had not been denied. The FAA inspector stated that the airplane was on approach to the south runway when it struck a power line that was about 27 feet above ground level and 360 feet from the approach end of the runway. The poles that support the power line were equipped with unlighted cones. The airplane came to rest about 75 feet short of the runway.