Mooney M-18C 55 N201MM accident near Napa, California

Probable cause

The pilot’s failure to use carburetor heat, which resulted in a loss of engine power due to carburetor icing and a subsequent impact with terrain during a forced landing.

NTSB analysis

The pilot was on an approach to the airport about 3,000 ft above ground level (agl) when the engine lost all power. The pilot cycled the throttle control to full, but the engine did not restart and the propeller continued to windmill. He then declared an emergency and initiated a forced landing onto an open field about 5 miles north of the runway. During the landing roll on unimproved terrain, the left wing struck a large rock and came to rest nose down. Subsequently, the left wing sustained substantial damage.

During recovery of the aircraft, about 20 gallons of fuel remained in its tanks; a postaccident examination of the airplane and engine did not reveal any preimpact mechanical anomalies.

The temperature at the airport, which was about 6 miles south of the accident site, was 63°F and the dew point was 52°F; the relative humidity was about 67%. A review of the icing probability chart contained within FAA Special Airworthiness Information Bulletin CE-09-35 revealed that the atmospheric conditions at the time of the accident were "conducive to serious icing at glide [idle] power." The pilot added that he did not use carburetor heat during the descent and approach and that he should have used a pre-landing checklist.

Text from the NTSB. Open the NTSB docket for WPR23LA202 for the full record.