On October 20, 2003, at 1818 eastern daylight time, a Godwin Lancair 360 experimental airplane, N797RP, registered to and operated by the private pilot, collided with a rock embankment during a forced landing at Sky Ranch Airport, Knoxville, Tennessee. The personal flight was operated under the provisions of Title 14 CFR Part 91 with no flight plan filed. Visual meteorological conditions prevailed. The private pilot received serious injuries, the private pilot-rated passenger received fatal injuries, and the airplane was destroyed. The flight was originating from Knoxville, Tennessee, at the time of the accident on October 20, 2003. According to the pilot, he performed a preflight and pre-takeoff runup of the airplane. He stated he performed one aborted takeoff to check the airplane and check the runway surface, then he taxied back and performed another runup of the airplane's engine. He stated he performed a takeoff and climb to the north, and about 10 seconds into the flight, the engine began to run rough. The pilot estimated the altitude was about 200 to 300 feet. He stated he executed an immediate 180-degree turn back toward the runway, and the engine continued to run rough. As the airplane neared the runway, the engine quit completely, and the airplane "dropped like a brick." The pilot stated he "pulled the nose up" and "couldn't see the runway," and he looked out the side window and saw the runway. He stated that within seconds, the airplane collided with the ground, and he blacked out. A certified flight instructor-rated witness observed the airplane on final approach to the south-oriented runway and stated the airplane was "low and slow." The airplane collided with a rock river embankment approximately two feet below the runway elevation. The wreckage came to rest in the grass above the embankment and a few yards short of the runway. Examination of the accident site revealed scrape marks on the river embankment rocks. The fuselage was separated aft of the cabin, the cabin and wings were fragmented, and the engine was inverted. The nose of the airplane was crushed, and debris from the airplane was scattered across the grass south of the embankment. Fuel odor was detected at the accident site. Both propeller blades were damaged on the leading and trailing edges. One blade was bent forward with the tip separated, and the other blade was bent aft. The engine remained attached to the firewall, the engine mounts were bent, and the engine control cables were damaged. Examination of the engine revealed the crankshaft flange was fractured. The flange was cut with tools and the propeller was removed to facilitate examination. The crankshaft was rotated at the flange, and continuity of the crankshaft, camshaft, valve train, and accessory drives was established. Compression developed on all cylinders. Borescope examination of the piston domes, valves, and cylinder walls revealed no evidence of abnormality. The oil sump was damaged and breached, and the lower exhaust pipes were crushed. The oil filter was free of contaminants, the oil cooler and oil cooler hoses were secure. The spark plug electrodes exhibited gray-colored combustion deposits with no evidence of abnormality. Both magnetos produced spark through all ignition leads when turned by hand. The fuel injector inlet screen and main fuel strainer were free of contaminants, and trace amounts of fuel were found in the fuel flow divider and fuel servo. The induction air scoop to the fuel servo and air manifold to the cylinders were damaged. The engine-driven fuel pump operated when turned by hand, and the electric fuel pump operated when power was supplied. The propeller governor adapter was fractured, and the control arm was separated. The propeller governor drive gears and coupling were intact, and the unit rotated when turned by hand. The gasket screen was free of contaminants, oil was present, and pumping action was observed. Examination of the engine maintenance logs revealed the HIO-360-C1A engine was formerly installed on an Enstrom helicopter. The data plate for the engine was found with the logs. Examination of the helicopter engine log revealed a field major overhaul was completed December 19, 1979, at an engine total time of 1165.7. An entry in the helicopter engine log dated December 7, 1992, recorded the engine total time as 1289.0; there were no further helicopter log entries for the engine. Examination of an engine log that listed the engine as equipment on the Lancair 360 revealed the first entry in the log was dated July 30, 1998; the entry recorded the "tach" time as 02 and "total time in service" as 250. An engine log entry dated October 19, 2003, recorded the "tach" time as 134. The hour meter reading at the accident site was 134.9.