BOEING A75N1(PT17)

Full Narrative

On November 18, 2024, about 1630 eastern standard time, a Boeing A75N1, N55464, was substantially damaged when it was involved in an accident near Huntington, West Virginia. The private pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.
The pilot departed from Robert Newlon Field (I41), Huntington, West Virginia, about 1615. He reported that he and a friend in a second airplane of a similar make and model were going to fly together on a local flight. Shortly after departing, the pilot reduced the throttle to slow down and wait for the second airplane to catch up while at an altitude about 1,800 ft above ground level. After having the engine at a reduced power setting for an “extended” amount of time, the engine suddenly lost total power. Unable to restart the engine, the pilot made a forced landing into a railroad yard. During the landing attempt, the empennage impacted a tree and forced the airplane nose down into the terrain.
A postaccident examination of the airplane and engine was conducted after it had been recovered from the accident site. Both upper and lower wings had been removed from the fuselage and were not present during the airframe examination. The airplane was resting on its lower fuselage and right horizontal stabilizer. The left main landing gear was partially attached to the fuselage and the right main landing gear was separated from the fuselage and lying beside the airplane. The engine mounts were bent in several places, and the engine was displaced down. The wooden propeller remained attached to the engine with one blade tip broken and splintered. There were no rotational signatures noted on the propeller blades.
The airplane was equipped with a fuel tank mounted above the fuselage, between the upper wing structure. The fuel tank cap was installed. The fuel tank cap o-ring was dry and cracked. The fuel tank had two sump locations and automotive fuel came out of both locations. The fuel tank delivery system sent fuel to the fuel shutoff location forward and to the left of the forward cockpit seat. Minor blue fuel staining was present at the fuel petcock. From the fuel petcock, the fuel line was routed through the engine firewall to a fuel strainer. The fuel strainer was mounted to an engine mount tube and was displaced upward but was undamaged. The strainer contained about 1 cup of automotive fuel when opened. The strainer was clean with no debris found internally. The fuel system went from the strainer to the engine carburetor. The carburetor was damaged and displaced consistent with impact forces. The fuel inlet screen of the carburetor was examined, and no debris was noted. The carburetor was removed and examined. The throttle and mixture levers were manipulated by hand and no binding was noted. The throttle and mixture cables were attached to the carburetor. Both lines were bent and broken at the connection points forward of the firewall. Continuity of the throttle, mixture, and carburetor heat cables was visually established.
The 7-cylinder radial engine appeared to be visually undamaged, and the bottom-most cylinder had organic debris pressed into the cooling fins. The forward spark plugs were removed, and the electrodes were normal. The spark plugs displayed coloration consistent with normal engine operation. The magneto timing was checked and found to be within the engine manufacturer’s specifications. The crankshaft was rotated 720° by hand and thumb compression was established on all cylinders. Both magnetos were removed and both produced sparks at all leads when rotated with an electric drill. The engine oil tank held several quarts of oil, but the oil level gauge could not be read. The remote engine oil filter was attached to the firewall and was undamaged. The oil filter was opened and no contamination or debris was noted.
The engine intake plumbing was undamaged to the filter location. The induction filter was removed and was clean. The induction system was impact damaged at the carburetor. The carburetor air balance valve cable was attached, but bent, and visual continuity of the control was established. The engine exhaust system was undamaged.
The pilot was present for a portion of the engine examination. He commented that if there was no catastrophic engine failure, he believed that he may have experienced carburetor icing during his extended reduced power setting. He also noted that he did not apply carburetor heat before or after the loss of engine power. A review of the carburetor probability chart showed that the atmospheric conditions were conducive to the development of serious icing at glide power at the time of the accident.