On July 29, 1994, at 0930 central daylight time, a Cessna 421C, N819RA, registered to Pro Aviation, Ltd. of Ogden, Utah, experienced a hard landing on runway 27 (6,166' x 150' dry/concrete) at Wittman Field, Oshkosh, Wisconsin. The airplane received substantial damage. The private pilot and three passengers received no injuries. The personal 14 CFR Part 91 flight was operating in visual meteorological conditions. An IFR flight plan was on file. The flight departed Omaha, Nebraska, at 0730. In his written statement the pilot stated that he felt that the right main tire was "flat or blown out prior to landing or that it blew on initial contact, at touchdown." The Federal Aviation Administration (FAA) investigator at the accident scene found wrinkles in the wing between the engine nacelle and the fuselage. He questioned the pilot how this damage occurred. The pilot told him that the landing was hard. The FAA investigator inspected the tire and brakes on the airplane and found no mechanical anomalies or indication of pre-impact failure of the brakes or the right main tire