COLUMBIA, SC, USA
N803DR
Roebuck RANS S-10 SAKOTA
After takeoff, the airplane developed an engine compartment fire that spread to the fuselage after the airplane landed. According to an FAA inspector, there were blue vinyl/plastic tubing lines in the engine compartment, close to the exhaust pipes. There was evidence these lines began burning after being exposed to heat from the exhaust. The kit manufacturer stated that these lines were not supposed to be used forward of the firewall, and all lines within the engine compartment should have been routed according to engineering drawings and common sense. The owner/pilot/builder stated the drawings that he received depicted the blue tubing lines as part of the cooling and oil venting system, inside the engine compartment. He also stated that the engineering drawings he received for the routing of lines within the engine compartment were not based on the engine used in his airplane. Drawings provided to the Safety Board by the kit manufacturer showed the blue lines as part of the cooling system within the engine compartment.
On November 22, 1997, about 1130 eastern standard time, an amateur built David L. Roebuck Rans S-10 Sakota, N803DR, experienced an engine compartment fire during the initial climb after takeoff. The airplane was operated by the pilot/owner under the provisions of Title 14 CFR Part 91, and visual flight rules. Visual meteorological conditions prevailed. The private pilot and one passenger were not injured, and the airplane was substantially damaged. A flight plan was not filed for the personal flight. The flight was originating at the time of the accident. After takeoff, about 800 feet above ground level, smoke was observed in the cockpit. The pilot stated he immediately turned off the electrical switches and magnetos, and returned to the runway. The airplane landed safely. On evacuation, the pilot stated there were flames confined to the bottom of the fuselage, but they quickly spread to the fuselage and right wing. The fuselage and right wing were destroyed by the fire before the fire was extinguished with hand held fire extinguishers. According to the FAA inspector, there were blue colored, vinyl/plastic tubing lines in the engine compartment, close to the exhaust pipes. These lines caught fire after being exposed to the heat of the exhaust. According to the FAA, when the burning lines dropped to the bottom of the engine cowling the fabric of the fuselage also caught fire. This allowed the fire to spread to the remainder of the fuselage. The FAA inspector tested the tubing material and determined it was flammable. He also determined the melted plastic maintained a flame when it was dropped. According to the kit manufacturer for the RANS S-10 Sakota, the blue colored, vinyl/plastic tubing lines are designed to be used in the fuel system. They route the fuel from the fuel tanks to the fuel filters and forward to the firewall. There are separate black, fire resistant lines that are supposed to be used forward of the firewall. According to RANS, the routing of lines within the engine is left to the builder, and common sense should be applied. According to the owner/builder of the airplane, there were black, fire resistant lines in the engine compartment for the fuel system, but the blue, vinyl/plastic lines were also used forward of the firewall. According to the drawings the builder received from the RANS company, the flammable blue lines were intended to be used forward of the firewall as part of the cooling and oil venting system. The builder stated that he followed the drawings of the kit manufacturer in the construction of the airplane, but the engine drawings were based on a smaller engine, the Rotax 582. According to the builder, when he requested drawings for the Rotax 912, the kit manufacturer indicated that they did not produce any drawings for that engine. The builder indicated that he routed the lines using the drawings he was given for the Rotax 582 and through numerous calls to the customer support division at RANS. In a engineering drawing supplied by the RANS company to the Safety Board, the blue plastic/vinyl lines believed by the FAA to be flammable were found forward of the firewall as part of the cooling system. In the drawing, the blue plastic/vinyl line was a 1/4 inch fuel line, Part Number FS-FL-24, labeled as #17. According to the drawing, it was used to connect the coolant recovery bottle to a 1/4 inch aluminum tube.
the airplane builder's improper routing of vinyl/plastic cooling/vent line(s) for the engine oil system, and improper materials supplied by the manufacturer, which led to overheating of the line(s) in the engine compartment and an in-flight fire.
Source: NTSB Aviation Accident Database
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