FAA Ground School Practice Test

What is the impact of high humidity on the development of carburetor icing?

1. It reduces the likelihood of icing

2. It does not affect icing development

3. It increases the likelihood of icing

4. It only causes icing at lower temperatures

The correct answer is: It increases the likelihood of icing

High humidity significantly increases the likelihood of carburetor icing. This occurs because carburetor icing is influenced by the temperature and moisture in the air. When humid air passes through a carburetor, the moisture can condense and freeze when the temperature drops, especially during the fuel vaporization process, which further cools the air-fuel mixture. In high humidity conditions, the presence of excess moisture creates a greater chance for ice formation within the carburetor, which can disrupt the airflow and lead to engine performance issues. This is particularly relevant even at temperatures that might traditionally be considered too warm for icing, as the interplay of humidity and cooling effects still plays a crucial role. Therefore, understanding that high humidity enhances the conditions leading to carburetor icing is essential for safe flight operation and proper aircraft performance management.