On May 14, 2004, at 1200 Pacific daylight time, a Downer Bellanca 14-19-2 single-engine airplane, N7658B, impacted sagebrush during a forced landing following a loss of engine power 10 miles north of Lancaster, California. The airplane was registered to, and operated by the pilot under the provisions of 14 CFR Part 91. The airplane was substantially damaged. The commercial pilot and passenger sustained minor injuries. Visual meteorological conditions prevailed and a flight plan had not been filed for the personal flight. The local flight departed the General WM. J. Fox Airfield, Lancaster, approximately 1030. During a telephone interview conducted by the National Transportation Safety Board investigator-in-charge (IIC), the pilot stated he was in cruise flight at 1,000 feet above ground level when the airplane lost engine power. The pilot switched the fuel selector from the auxiliary fuel tank to one of the other wing fuel tanks, though he could not specifically remember which one he initially selected. The pilot also activated the manual wobble pump and obtained a few engine surges, but power could not be regained. The pilot set up for a forced landing to sandy area with low sagebrush. During the landing sequence, the airplane impacted some brush and the landing gear and firewall sustained substantial damage. In a written statement provided by the pilot, he indicated the engine lost power "in a manner indicative of fuel starvation." At the time of power loss, the pilot was feeding the engine fuel from the auxiliary fuel tank. He then moved the "appropriate fuel selector" from "off to right tank." He also moved the auxiliary fuel selector from "on to off." The pilot attempted to raise fuel pressure by utilizing the wobble pump. The engine developed power for "less than a second." The pilot them moved the fuel selector to the left fuel tank and utilized the wobble pump again. The engine did not respond and the pilot concentrated on the ensuing forced landing. After landing, the pilot placed both fuel selectors (one main fuel tank selector for the selection of the left and right main fuel tanks, and one for the selection of the auxiliary fuel tank) to the 12 o'clock position. It should be noted that the 12 o'clock position for the main fuel tank selector is OFF, and the 12 o'clock position for the auxiliary fuel tank is ON. The airplane was transported back to the pilot's hangar for further examination. According to the salvage facility, 10 gallons of fuel were removed from the left fuel tank, 15 gallons of fuel were removed from the right fuel tank, and no fuel was found in the auxiliary fuel tank. The 230-horsepower Continental O-470-K engine (serial number 47800-7-K) had accumulated a total of 1,435.8 hours since new and 103.3 hours since its last overhaul. The last annual inspection was conducted on May 17, 2003, at an aircraft and engine total time of 1,353.35 hours. On May 18, 2004, the aircraft was examined by two FAA inspectors and an investigator from Continental Motors. According to the Continental investigator, no fuel was found in the gascolator or any of the fuel lines forward of the firewall. The carburetor bowl drain plug was removed and no fuel was present in the carburetor bowl. The top spark plugs were removed and visually examined. All were light whitish/gray in color and exhibited nominal electrode erosion and gapping. All of the piston domes were examined and displayed the same color as the spark plugs. The crankshaft was manually rotated and all six cylinders produced compression. Both magnetos produced a spark during the crankshaft's rotation. Removal of the engine driven fuel pump revealed the drive coupling and pump vanes were in place and intact. Review of the aircraft's operation manual revealed the following statement regarding the auxiliary fuel system: "The auxiliary fuel tank should not be completely emptied in flight. If it is left on and permitted to run dry, air will be pumped into the fuel line."