Cessna 150 N704QJ accident near Red Rock, Arizona

Probable cause

A total loss of engine power due to carburetor icing. Contributing to the accident was the pilot’s improper use of carburetor heat.

NTSB analysis

The pilot reported that he recently purchased the airplane, and the accident flight was a familiarization flight. After taking off, he conducted some maneuvers before proceeding to another airport to perform a touch-and-go landing. About 6 miles away from the airport, he reduced the power setting to about 1,900 rpm and started the descent to land; about 1 mile from the airport, he reduced power to 1,500 rpm, and then idle on final approach. He stated that he applied carburetor heat about halfway to reduce its effect on engine performance. During takeoff following the touch-and-go landing, the airplane started to shake, and about 1,500 ft above the ground, the engine lost total power. The pilot performed a forced landing to a field; during which the nose landing gear collapsed, resulting in substantial damage.

About 8 gallons of fuel was drained from the airplane during recovery. The engine was rotated by hand at the propeller, and internal continuity and cylinder compression was confirmed. The atmospheric conditions at the time of the accident were conducive to the development of carburetor icing at glide power settings. Given that the pilot extended the carburetor heat control only halfway, the heat applied was likely insufficient to prevent the formation of carburetor ice during the reduced power descent toward the airport, and the subsequent total loss of power was the result of carburetor icing.

Text from the NTSB. Open the NTSB docket for WPR20LA022 for the full record.