Accident Overview
On November 11, 2023, at about 0815 eastern standard time, a Taylorcraft BC12-65 airplane, registration N29868, sustained substantial damage during an accident near Columbia, Tennessee. The private pilot incurred minor injuries. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
Pilot Report
The pilot reported performing a preflight inspection and confirming approximately 12 gallons of fuel on board. Engine start, taxi, and pretakeoff runup operations lasted about 25 minutes with no anomalies. Before takeoff, the pilot activated the carburetor heat and observed a normal engine rpm drop. He left the carburetor heat applied for a little longer and, when turning it off, noted no change in engine rpm. During takeoff, power application resulted in strong and smooth acceleration. At an altitude of about 25-30 ft above ground during the initial climb, the engine suddenly lost about 1,000 rpm. The pilot elected to perform an off-field landing, maneuvering to avoid a hedgerow. The airplane touched down in an area of high grass, and substantial damage occurred during the landing sequence. First responders met the pilot.
Post-Accident Examination
The wreckage was examined after recovery to a storage facility. The wing and main fuel tanks contained fuel and were intact. Fuel drained from the tanks was clean and free of water or other contaminants. The carburetor bowl contained a small amount of particulate matter, but the carburetor inlet screen was clear. The engine was turned manually by rotating the propeller. Compression and suction were noted on all four cylinders, and valve action was correct. The magnetos produced spark to all leads when operated manually. Spark plugs were normal in color and wear compared to a Champion inspection chart. The carburetor was broken from the engine consistent with impact damage; however, cockpit controls remained attached. The carburetor heat knob was found in the off position.
Examination of the fuel system and engine did not reveal evidence of a preexisting anomaly or failure that would have precluded normal operation.
Weather and Carburetor Icing Considerations
The recorded temperature and dew point near the accident site were about 48°F and 35°F, respectively. On a carburetor icing probability chart, those temperatures fall in the “serious icing – cruise power” range. An FAA Special Airworthiness Information Bulletin (CE-09-35) – Carburetor Icing Prevention, notes that carburetor icing can occur at temperatures above freezing due to fuel vaporization and air expansion in the carburetor (Venturi effect), causing sudden cooling. Carburetor ice may be detected by a drop in rpm in fixed-pitch propeller airplanes, often accompanied by rough engine operation.