How does carburetor icing occur?

Carburetor icing occurs as a result of the principles of thermodynamics and the characteristics of air-fuel mixtures. When air passes through the carburetor, it experiences a drop in pressure due to the Venturi effect, which leads to a decrease in temperature. If there is moisture present in the air, the cooling effect can cause this moisture to freeze, forming ice within the carburetor. This ice can obstruct the flow of air and fuel, leading to engine performance issues.

The conditions conducive to carburetor icing typically occur in temperatures between 20°F and 70°F, especially when the relative humidity is high. In this context, carburetor icing is not influenced by intense heat, rapid fuel evaporation at high temperatures, or mechanical failures in the carburetor itself. Understanding these conditions is critical for pilots to recognize and prevent carburetor icing in various flight environments.