History of Flight On June 10, 1997, at 1315 central daylight time (CDT), an experimental Siefert 5151RG, N81728, was destroyed when it impacted the ground and burned. The commercial pilot had departed at 1300 from the Shelbyville Municipal Airport, Shelbyville, Indiana, en route to his private grass airstrip about eight miles away. The airplane impacted the ground about one half mile from the grass airstrip. The pilot had received fatal injuries. Visual meteorological conditions prevailed and no flight plan was filed. A witness observed the airplane depart Shelbyville Municipal Airport. The witness reported that the engine sounded fine and the airplane appeared to be flying normally. At 1800, the airplane was reported missing. A pilot who was flying in the local area proceeded to the grass airstrip to search for the airplane. The pilot observed the airplane wreckage in a recently planted soybean field. There were no witnesses to the accident. Personnel Information The 71 year old pilot had a commercial pilot certificate with an instrument rating. He was a certified flight instructor with airplane and instrument instructor ratings. He had a total of about 5,091 total flight hours. The pilot had a current Biennial Flight Review (BFR). The pilot's logbook did not indicate that he had flown since the BFR. A witness reported that the pilot had flown about 5 hours in the accident aircraft. Aircraft Information The airplane was a Siefert 5151RG with a 582 Rotax engine. The airplane was issued a Special Airworthiness Certificate in the Experimental category on April 24, 1997. The airframe and engine had about 5 hours of total time. The airplane was a wooden kit airplane that was designed by Loehle Aircraft Corporation. Aircraft logs indicate the pilot had started work on the airplane in 1991 and had completed the airplane on April 24, 1997. Witnesses reported the Siefert 5151RG was the second aircraft that the pilot had built. The first airplane the pilot built was an Acro-Sport. Witnesses reported that the pilot initially had problems getting the Center of Gravity (C.G.) within the proper C.G. range. The pilot installed about 40 pounds of lead ballast to the engine box of the airplane to get the C.G. into the proper C.G. range. The lead ballast had been added to the airplane before the first flight. Witnesses reported that the pilot had modified the fuel system by installing an electronic fuel boost pump to the engine. Fire damage destroyed the fuel lines and it was not determined if the electric boost pump was routed in series with the impulse fuel pump or in parallel with the fuel pump. Witnesses reported that the pilot made at least five flights in the aircraft. Witnesses reported that the pilot had kept the landing gear extended on all the flights and had not retracted them while airborne. The Vne of the airplane was 100 mph and cruise speed was 75 mph. Wreckage and Impact Information The accident site was located in a soybean field about 1/2 mile from the pilot's grass airstrip. The aircraft's heading prior to impact was approximately 315 degrees. The airplane's wooden and fabric covered fuselage was destroyed by the fire. The engine and propeller were torn from their mounts and had also received fire damage. There were five prop strikes about 12 inches apart leading to the sheared off propeller blades and engine. The aircraft was found in the inverted position about eight feet from the first propeller strike. The impact angle was about 15 degrees nose down. The landing gear was extended. The examination of the engine revealed no anomalies. The examination of the airframe revealed that the pilot had modified the control surface's hinge pins provided by the kit manufacturer by replacing the hinge pins with 3/8 inch cotter keys. The flight controls had continuity. Medical and Pathological Information An autopsy was performed on the pilot at the Indiana University School of Medicine, Department of Pathology. A Forensic Toxicology Fatal Accident Report was prepared by the FAA Civil Aeromedical Institute. The report indicated the following results: The results of the toxicology examination were negative. Additional Information Parties to the investigation included the Federal Aviation Administration, Action Consulting Enterprises Canada, and Loehle Aircraft Corporation.