On June 29, 2012, at 0829 central daylight time, an amateur-built Badeaux Challenger II, N16665, collided with a powerline while landing on private property in New Iberia, Louisiana. The non-certificated pilot was seriously injured and the aircraft was substantially damaged. The aircraft 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 for the flight, which was not operated on a flight plan. The local flight originated in New Iberia, Louisiana, about 0832. The pilot reported that he knew there were two powerlines that he needed to cross during the approach to land at his private airstrip. He stated he thought he had crossed both powerlines during the approach, when in fact he had only crossed one. When he saw the second powerline he added power and attempted to climb; however, the tailwheel struck the powerline and the airplane subsequently impacted the terrain. The pilot reported that both powerlines were approximately 40 feet tall and they were separated by approximately 200 feet. The aircraft had been registered, but it did not have an airworthiness certificate at the time of the accident. The pilot reported he had flown the aircraft about 5 times prior to the accident, which was the extent of his flight experience with the exception of having flown large scale remote control airplanes.