The Probability Of Carburetor Icing Was “Serious” At Cruise Power

Location: Margarettsville, NC Accident Number: ERA22LA046
Date & Time: November 4, 2021, 19:30 Local Registration: N704HQ
Aircraft: Cessna 150M Injuries: 1 None
Flight Conducted Under: Part 91: General aviation – Personal

On November 4, 2021, at 1930 eastern daylight time, a Cessna 150M, N704HQ, was substantially damaged when it was involved in an accident near Margarettsville, North Carolina. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The pilot reported that after descending to about 1,600 ft mean sea level, while on the localizer approach to runway 34 at the Emporia-Greensville Regional Airport (EMV), Emporia, Virginia, the engine began to “sputter.” He applied the carburetor heat, the engine “got a little surge of power,” and he pushed the carburetor heat back in (OFF). The engine sputtered again, and he re-applied the carburetor heat. He then raised the nose to gain altitude, and the engine stopped completely. He turned the airplane toward a road he had recently overflown, declared an
emergency, and landed in the tree canopy about 10 nautical miles southeast of EMV.

A post-accident examination of the airplane revealed that the throttle, mixture, and carburetor heat controls remained intact and functioned normally. Fuel drained from the carburetor was blue in color with no water or debris present. The top sparkplugs were removed, their
electrodes were grey in color and appeared “worn normal” when compared to a Champion Check-a-Plug Chart.

Fuel was plumbed into to engine from an external fuel tank to the carburetor. The engine was primed, started, ran at idle without anomaly, and responded to throttle inputs. The 1935 weather observations reported at EMV included a temperature 6°C and dew point of 5°C. A review of a carburetor icing probability chart revealed that in those conditions, the probability of carburetor icing was “serious” at cruise power.