What primarily causes carburetor icing?

The primary cause of carburetor icing is indeed related to fuel vaporization and air expansion. When fuel is drawn into the carburetor, it vaporizes as it mixes with the incoming air. This process is endothermic, meaning it absorbs heat from the surrounding environment. As the temperature drops during this vaporization and the expansion of the air, it can create conditions that lead to the formation of ice in the carburetor, particularly in high humidity conditions where moisture is available.

Carburetor icing can occur at temperatures above freezing, typically in high-humidity situations, making it a critical consideration for pilots flying in certain conditions. Recognizing this mechanism helps pilots anticipate and manage the risks associated with carburetor icing in their operations. Understanding both the principles of fuel behavior and the environmental conditions contributing to icing is key for effective aircraft operation and safety.