What is "carburetor icing"?

Carburetor icing refers to the phenomenon where ice forms within the carburetor due to the temperature drop that occurs during the vaporization of fuel. When the fuel passes through the venturi (a narrowing in the carburetor), it expands and vaporizes, which causes a drop in temperature. This drop can lead to conditions conducive to ice formation, particularly in humid air. As ice accumulates in the carburetor, it can restrict the airflow and negatively impact engine performance, leading to potential engine failure if not properly managed.

Understanding this concept is crucial for pilots, especially during flight conditions where the air temperature is near freezing or in conditions of high humidity, as this knowledge helps in diagnosing and preventing engine issues related to carburetor icing.