On September 10, 2008, about 1050 Pacific daylight time, an experimental amateur built Miltenberger Family Fun, N903PD, impacted terrain near Adin, California. The pilot/owner was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The pilot was not injured and the passenger sustained minor injuries. The airplane sustained substantial damage to the right landing gear and its attach point. The cross-country personal flight departed Albany, Oregon (S12), about 0810, with a planned destination of Carson City, Nevada (CXP). Visual meteorological conditions prevailed, and no flight plan had been filed. The pilot reported that about 2 hours into the flight, and at 9,500 feet mean sea level (msl), the pilot detected an odor that smelled like a hot engine. The pilot reduced engine power from 4,200 rpm to 3,800 - 3,900 rpm, and the odor went away. Carburetor heat was not applied. Shortly thereafter, the engine started running rough. The pilot still did not apply carburetor heat. The pilot thought the engine would quit, so he executed an emergency landing in a field. During the landing the airplane impacted a wire fence. The pilot stated that the Ford 3.8 V-6 engine was susceptible to carburetor ice due to the carburetor installation. The closest weather reporting station noted the temperature was 68 degrees and the dew point was 34 degrees. The intersection of these two temperatures on a carburetor icing probability chart is right at the boundary between the two sections annotated "light icing cruise power" and "serious icing glide power". The pilot submitted a Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2) on September 18, 2008. The pilot reported the following damage: The right landing gear was knocked off; the frame was bent where the right landing gear attached; the tail wheel broke off; and the prop was damaged. The pilot reported that the airplane and engine had no other mechanical failures or malfunctions during the flight. According to FAA Advisory Circular AC 20-27F, Certification and Operation of Amateur-Built Aircraft, "Amateur builders are free to develop their own designs or build from existing designs. We do not approve these designs and it would be impractical to develop design standards for the wide variety of design configurations, created by designers, kit manufacturers, and amateur builders."