CEN25FA040

On November 15, 2024, about 1000 mountain standard time (MST), a Beech 35-B33, N285BW, was destroyed when it was involved in an accident near Nunn, Colorado. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The flight originated from Chadron Municipal Airport (KCDR), Chadron, Nebraska, with an intended destination of Platte Valley Airport (18V), Hudson, Colorado; a distance of about 180 nautical miles (nm). No ADS-B, radar data, or ATC communications were obtained at the time of the on site investigation. Day visual meteorological conditions prevailed along the entire route of flight. The accident site was in a farm field about 3.5 miles north-northwest of Nunn, Colorado, about 20 nm west of a direct route between the start point and intended destination. The debris field was roughly 500 ft long by 400 ft wide. The initial point of impact contained a fragment of the left wingtip fuel tank fairing. A line of disturbed dirt continued from the initial point of impact for about 25 ft to a 17-foot-long impact crater. The line of disturbed dirt continued beyond the crater another 10-15 ft. Fragments of the outboard section of left wing and other airplane components were strewn throughout the debris field leading up to the main wreckage which was located about 258 ft from the initial point of impact. All the major components of the airplane were accounted for at the accident site. No anomalies were noted in the examined airframe components. The No. 6 cylinder separated from the engine. The interior of the No. 6 cylinder and the valve faces looked normal. The No. 2 & 4 cylinders were displaced aft and had fractured the case of the engine open. Visual examination of the interior of the engine showed no signs of thermal distress; the camshaft appeared normal; and no signs of a pre-impact failure or malfunction were noted. The crankshaft counterweights were present and moved freely. The oil sump housing was fractured and the front third of the sump housing had separated; no pre-impact anomalies were noted inside. The propeller hub remained attached to the crankshaft flange but had fragmented. Pieces of the hub and both propeller blades were present in the debris field. The propeller blades both had blade twisting, leading edge nicks and gouges, chord wise scratching, and blade polishing. Spiral cracking was noted on the engine crankshaft just aft of the propeller mounting flange. A Garmin 396 was retained for further examination. The wreckage was scheduled to be recovered and stored for further examination.