Cubcrafters CC11-160 N71BN accident near Lancaster, Ohio

Probable cause

The delayed application of carburetor heat by the pilot which led to accumulation of carburetor ice, eventual loss of engine power, and the subsequent forced landing in high vegetation.

NTSB analysis

The pilot reported that while descending from cruise flight to traffic pattern altitude, the airplane's engine began to run rough. He applied carburetor heat which made the roughness worse and when he then turned off carburetor heat, the engine lost all power. The pilot executed a forced landing to a farm field where the airplane nosed over in the high vegetation.

According to a carburetor icing probability chart, the temperature and dew point were in the range of susceptibility for serious carburetor icing at descent power settings. The pilot's report of the accident listed no mechanical malfunctions or failures of the airplane, and a recommendation to apply carburetor heat earlier at the beginning of the descent.

Based on the information available the airplane's engine likely lost power due to accumulation of carburetor ice due to the delayed application of carburetor heat.

Text from the NTSB. Open the NTSB docket for CEN18LA370 for the full record.