On April 26, 2003, about 1145 mountain standard time, a Cessna 180A, N9759B, experienced a gear failure while attempting to land at Scottsdale Airport (SDL), Scottsdale, Arizona. The pilot/owner was operating the airplane under the provisions of 14 CFR Part 91. The private-pilot, the sole occupant, was not injured; the airplane sustained substantial damage. Visual meteorological conditions prevailed and a flight plan had not been filed. The personal local flight departed SDL about 1015. In a written statement, the pilot reported that he was attempting to make a wheel landing on runway 21. After a normal touchdown, the airplane lurched to the left and the right main landing gear wheel departed the airplane. The right main landing gear strut folded under the fuselage and the right wing tip contacted the runway surface. The airplane came to rest on its right side. The pilot thought that an "abrupt left brake grab" placed a side load on the right gear, which resulted in the failure of the right main landing gear wheel. The Federal Aviation Administration (FAA) maintenance inspector stated that the forward, upper bolt connecting the axle to the backing plate had sheered off. The other three bolts had twisted off, separating the wheel from the airplane, which he believe occurred after the initial bolt had failed. He thought it was possible that the bolts installed were the original bolts that the airplane was outfitted with in 1957. He believed there was a great possibility that the sheered bolt had failed due to its age and extended use.