On April 23, 2010, at 1330 Pacific daylight time, a restricted category Grumman Aircraft Engineering G164A, N4450, lost engine power in flight and was substantially damaged during a forced landing approximately 2 miles north of Madera Municipal Airport, Madera, California. The commercial pilot was operating the airplane under the provisions of Title 14 Code of Federal Regulations Part 91. The pilot was not injured. Visual meteorological conditions prevailed and no flight plan was filed for the positioning flight. The pilot departed from Lodi Airport, Lodi, California, and was en route to Shirley Williams Airport, Kingsland, Texas. His next planned stop was Fresno Chandler Executive Airport, Fresno, California. According to the pilot, he recently purchased the airplane and was ferrying it home. He made a fuel stop and then flew approximately 1 hour when the loss of engine power occurred. While established in cruise flight at 1,500 feet above ground level, the engine lost power. The pilot pushed the engine and propeller controls forward and looked for a place to land. He attempted to land at Madera but force-landed the airplane in a pistachio orchard where the airplane came to rest inverted. From the time of his initial departure, the pilot had flown 1.8 hours in the airplane. The last annual inspection was completed in January 2010 and the airplane had not been flown since that time. The Federal Aviation Administration inspector examined the airplane and engine with a representative from Pratt and Whitney. The exhaust turbine wheel rotated freely. The engine was manually rotated with no unusual sounds from the power or compressor turbines. The main fuel filter was removed showing no water or other contamination. The fuel selector was found in the "On" position and the inspector noted difficulty in rotating the selector from the "On" to the "Off" position. The fuel control unit and fuel pump were removed from the engine and sent to Pratt and Whitney Canada for further examination and testing. Representatives from the Transportation Safety Board of Canada and Pratt and Whitney examined the fuel control unit and fuel pump. Trace amounts of contaminants were found in the fuel pump inlet and outlet filter. Testing of the fuel control unit and fuel pump revealed no mechanical anomalies.