What happened
On November 15, 2024, at approximately 10:00 MST, a Beech 35-B33, registration N285BW, crashed in a farm field about 3.5 miles north-northwest of Nunn, Colorado. The flight was being operated under 14 CFR Part 91 as a personal flight, departing from Chadron Municipal Airport (KCDR) in Nebraska with an intended destination of Platte Valley Airport (18V) in Hudson, Colorado.
The aircraft was approximately 20 nautical miles west of its direct route when the accident occurred. Weather conditions during the flight were visual meteorological conditions (VMC) with a visibility of 10 statute miles and winds from 090 degrees at 3 knots. The pilot sustained 1 fatal injury.
The debris field measured approximately 500 feet long by 400 feet wide. The initial point of impact contained a fragment of the left wingtip fuel tank fairing, followed by a line of disturbed dirt and a 17-foot-long impact crater. The main wreckage was located approximately 258 feet from the initial point of impact.
The investigation
Investigators accounted for all major components of the aircraft at the site and found no anomalies in the examined airframe components.
Examination of the engine revealed that the No. 6 cylinder had separated from the engine, though the interior of the cylinder and valve faces appeared normal. The No. 2 and No. 4 cylinders were displaced aft, causing the engine case to fracture. There were no signs of thermal distress, pre-impact failure, or malfunction within the engine; the camshaft appeared normal, and the crankshaft counterweights moved freely. The oil sump housing was fractured and partially separated, but no pre-impact anomalies were found inside.
The propeller hub remained attached to the crankshaft flange but had fragmented. Both propeller blades were present in the debris field and exhibited twisting, leading edge nicks, gouges, chordwise scratching, and blade polishing. Additionally, spiral cracking was identified on the engine crankshaft just aft of the propeller mounting flange.