On October 1, 1999, at 1530 central daylight time, a Cessna 210L airplane, N2157S, was substantially damaged when the right main gear collapsed upon landing at the Northwest Arkansas Regional Airport, near Fayetteville, Arkansas. The non-instrument rated private pilot and his passenger were not injured. The airplane was registered to and operated by the pilot. Visual meteorological conditions prevailed for the 14 Code of Federal Regulations Part 91 personal flight and a flight plan was not filed. The cross-country flight originated from the Sally Wofford Airport, Weiner, Arkansas, at 1300. According to the pilot, when the airplane was 5 miles from the destination airport in Fayetteville, he was cleared to land on runway 16. He extended the landing gear while on a 1/2 mile final. He "heard the gear lock into position," and then visually confirmed that the landing gear had extended. Furthermore, the green light in the cockpit illuminated, confirming that the gear was extended. Upon touchdown, a noise was heard, and the passenger stated, "I think we had a blowout." The right wing tip contacted the pavement, and the airplane exited the runway surface to the right of the runway centerline. The airplane came to rest upright in a grassy area adjacent to the runway. Examination of the airplane, by an FAA certified mechanic revealed that the right horizontal stabilizer and elevator were "severely bent in an upward direction." The outboard leading edge skin and two nose ribs of the right wing were structurally damaged. Additionally, the tail tie down ring and two antennas mounted on the belly were damaged. The mechanic stated that the right main gear down lock switch (Cessna part number S1377-1) failed in the "closed" or "down locked" position. "Dried paint stripper and paint" were observed around the plunger portion of the switch, which prevented the plunger from extending.