Piper PA-28-140 N55620 accident near Maryland Heights, Missouri

Probable cause

The pilot’s failure to activate the carburetor heat while operating in conditions conducive to carburetor icing, which resulted in a loss of engine power due to carburetor ice.

NTSB analysis

As the airplane was approaching the destination airport for a night landing, a witness saw the airplane maneuvering as it passed overhead. She also remarked that the engine sounded like it was sputtering and thought that the pilot was attempting to land the airplane on the beach of a nearby lake. The airplane impacted the water and cartwheeled before sinking. A test run of the engine was conducted; the engine started and ran at various power settings. An examination of the airplane and engine revealed no preimpact anomalies that would have precluded normal operation. The temperature and dew point about the time of the accident indicated that the airplane was operating in conditions that were conducive to serious icing at glide power. The pilot was in an extended descent and most likely had the power on the engine reduced for the descent. Although the carburetor heat was found on it is unknown when the pilot activated the carburetor heat. The engine controls were in positions consistent with an attempt to restart the engine; it is likely that the loss of engine power was due to carburetor ice and that the carburetor heat was not activated until after the engine began to lose power.

Text from the NTSB. Open the NTSB docket for CEN13FA030 for the full record.