On December 8, 1990, a Beech 23C (registration N5147M) operated by Winchester, John L. was involved in an aviation accident near Dunlap, TN. Investigators recorded the probable cause as: THE PILOT'S FAILURE TO USE THE CARBURETOR HEAT PROPERLY, WHICH RESULTED IN THE FORMATION OF CARBURETOR ICE, FOLLOWED BY A COMPLETE LOSS OF ENGINE POWER. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
While cruising at 4,000 feet, the engine quit. Restart attempts failed, and the aircraft crashed into a rock pit, sustaining major structural damage to the undercarriage. Fuel was present in both tanks, and no mechanical issues were found. Carburetor icing was indicated as a possibility.
Accident Overview
During a cruise at an altitude of 4,000 feet, the aircraft's engine unexpectedly ceased operation. The pilot attempted to restart the engine but was unsuccessful. The aircraft subsequently descended and crashed into a rock pit. The impact caused major structural damage to the undercarriage.
Investigation Findings
Examination of the aircraft at the accident site revealed that fuel was present in both tanks. A thorough inspection of the airframe and engine did not disclose any mechanical problem that would have prevented normal operation. The engine was later subjected to a functional examination, during which it operated normally. However, the icing probability curve indicated the possibility of carburetor ice formation. The aircraft was equipped with an operational carburetor heat system.