Cessna 150 N19524 accident near Big Lake, Alaska

Probable cause

The pilot's failure to apply full carburetor heat while operating in conditions conducive to carburetor icing, which resulted in a total loss of engine power, a forced landing, and impact with a tree.

NTSB analysis

The pilot reported that while performing a straight-in visual approach, he applied partial carburetor heat, and retarded the throttle for the descent. The airplane became low on the approach profile and the pilot increased the throttle and the engine subsequently "coughed" and then lost all power. He attempted to make a forced landing on a road, but the left wing struck a tree branch and the airplane subsequently impacted a snowbank and then the road. The wings and fuselage sustained substantial damage.

The pilot reported that there were no mechanical malfunctions or failures with the airplane that would have precluded normal operation. He confirmed that the fuel tanks had sufficient fuel for the flight.

The pilot reported that the accident could have been prevented had he applied full carburetor heat.

The exact probability of carburetor icing was not able to be calculated for the accident site due to the closest weather observation station being 9 miles away. The relative humidity level at that weather station was 87% at an ambient temperature of 12°F at the time of the accident.

Text from the NTSB. Open the NTSB docket for ANC20CA016 for the full record.