On June 21, 2012, at 1300 central daylight time, a Cessna model 140A airplane, N9497A, was substantially damaged while landing at Walnut Ridge Regional Airport (KARG), Walnut Ridge, Arkansas. The commercial pilot sustained minor injuries. His passenger was not injured. The airplane was registered to and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91. Day visual meteorological conditions prevailed for the personal flight, which was operated without a flight plan. The flight departed the pilot's private airstrip near Walnut Ridge, Arkansas, about 1200. The pilot reported that he was practicing touch-and-go landings on runway 22 (6,001 feet by 150 feet, asphalt) when the accident occurred. He noted that he had completed 4 uneventful landings before the accident landing. The pilot stated that the tailwheel-equipped airplane encountered an "abrupt gust of wind" during the landing flare that lifted the tail, placing the airplane into a nose-low attitude. The airplane subsequently impacted the runway and nosed over onto its back. The engine firewall, vertical stabilizer, and rudder were substantially damaged during the accident. The pilot noted that there were no preimpact mechanical malfunctions or failures that would have precluded normal operation of the airplane. The pilot reported that during the accident flight he saw several "dust devils" in the agricultural fields surrounding the airport and attributed the wind gust encountered during the landing flare to one of these whirlwinds. At 1255, the airport's automated surface observing system reported the following weather conditions: wind 180 degrees at 11 knots; clear skies; visibility 10 miles; temperature 31 degrees Celsius; dew point 18 degrees Celsius; altimeter setting 29.97 inches of mercury. On June 22, 2012, an inspector with the Federal Aviation Administration conducted a postaccident examination of the airplane. The examination confirmed flight control continuity from the cockpit controls to the respective control surfaces and tailwheel assembly. Additionally, no mechanical anomalies were noted during a function test of the brake system. The postaccident examination did not reveal any preimpact mechanical malfunctions or failures that would have precluded normal operation of the airplane.