On April 15, 2005, approximately 1140 central daylight time, a Beech J35 single-engine airplane, N8396D, owned and operated by the pilot, sustained substantial damage during a forced landing following a loss of engine power near the Bartlesville Municipal Airport (BVO), near Bartlesville, Oklahoma. The instrument-rated commercial pilot and his passenger were not injured. Visual meteorological conditions prevailed and a flight plan was not filed for the personal flight, which was conducted under the provisions of 14 Code of Federal Regulations Part 91. The local flight departed from BVO at 1108. In a written statement, the 3,767-hour pilot reported that he was "getting ready to make a 180-degree turn for a 45-degree entry to a right downwind for runway 17 at BVO when the engine started sputtering." He immediately reached down and turned the fuel selector from the "left main" tank to what he thought was the "auxiliary" tank position. Subsequently, the engine stopped producing power. He then switched the auxiliary fuel pump to the "on" position, thinking that the engine would resume running momentarily, but it did not. The pilot then looked to the airport and realized that he would not be able to make it to the runway. The pilot added that he began to look for a suitable location for a forced landing. The pilot extended the airplane's landing gear and elected to land in a an open pasture. After the airplane touched down in the pasture, he observed a ditch on his path that he was unable to avoid. Subsequently, the nose gear collapsed, and the airplane nosed over, coming to rest in an inverted position. After the accident, the pilot discovered that he had turned the fuel selector to the "off" position, instead of the "auxiliary" position. Post inspection of the airplane by the pilot revealed that the engine firewall sustained structural damage. At 1153, the automated weather observing system at BVO reported variable wind at three knots, 10 statute miles visibility, a clear sky, temperature 71 degrees Fahrenheit, dew point 46 degrees Fahrenheit, and a barometric pressure setting of 30.26 inches of Mercury.