The Federal Aviation Administration (FAA) Inspector, who responded to an aircraft accident, reported that he found an unregistered, experimental, single-seat, amateur-built airplane lying inverted in an open field. The wood/fabric airplane had received extensive damage during the impact, and the inspector reported that it appeared that the airplane collided with terrain at a low-speed, high-angle. He added that fuel was present on-site. The private pilot received serious injuries during the crash. The pilot had reportedly purchased the partly completed airplane approximately two years prior to the accident. The airplane had not flown before; when the private pilot decided to test fly the airplane. The pilot pre-flighted the airplane and then taxied the airplane up and down a private airstrip, located near the pilot's residence. The pilot reported to the FAA Inspector, that shortly after take-off, the airplane's engine began to "sputter". The pilot attempted a forced landing to a nearby airstrip; however, the airplane stalled and impacted a field just short of the airstrip.