On November 10, 2010, about 1100 eastern standard time, an Aeronca 7AC, N82934, was substantially damaged during landing at Merritt Island Airport (COI), Merritt Island, Florida. The certificated airline transport pilot and passenger were not injured. The personal flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the local flight. The pilot reported that he was practicing landings at COI on runway 29, a 3,601-foot-long, 75-foot-wide, asphalt runway. After the last "smooth" landing, the airplane veered right. The pilot corrected with left rudder and the airplane initially corrected left; however, it then veered sharply right against the application of full left brake and ruder. The airplane subsequently departed the right side of the runway and came to rest upright in a creek. During the runway excursion, the left wingtip struck the water and ground. Examination of the wreckage by an insurance adjuster revealed that the main landing gear had separated and the left wingtip was bent upward. Additionally, the fuselage was distorted in the vicinity of the left wing root and the main landing gear structure. The adjuster also noted that a right main landing gear attachment point appeared "rusty." The right main landing gear attachment bracket and a support tube were forwarded to the NTSB Materials Laboratory, Washington, DC. Metallurgical examination revealed that the front portion of the attachment bracket displayed buckling, bending, cracks on the tension side of the bend, and displacement of material around the hole, consistent with an overload event. Minor corrosion pitting was observed on what was left of the outboard portion of the bracket. The upper end of the support tube, as originally installed, was circular with slant fracture features consistent with an overload event. The lower end of the tube was an oval shape, with an increasing reduction in tube diameter on one axis as it approached the fracture face, and also displayed slant features consistent with an overload event. The wind was reported as calm at an airport located approximately 8 miles south of the accident site, about the time of the accident.