On August 10, 2014, about 1220 Pacific daylight time, a Nelson RV-3M airplane, N43AZ, was substantially damaged when it was involved in an accident near North Plains, Oregon. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that, after a thorough preflight inspection, he taxied the airplane to the run-up area with the right fuel tank selected. He then switched to the left fuel tank for the run-up process, and all indications were normal. He then switched back to the right fuel tank and took off. When the airplane reached about 200 ft above ground level, he made a left turn, and the engine power reduced to about 1,000 rpm. The pilot chose to initiate a precautionary landing to a field during which the landing gear folded up beneath and into the bottom of the wings that resulted in substantial damaged to both wings and the fuselage. Subsequently, the airplane slid about 100 yards before coming to a rest. One inch of fuel was found in the left-wing fuel tank, and no fuel was found in the right-wing fuel tank. Evidence was found that fuel had drained out of the airplane.