Commercial Pilot License (CPL) Practice Exam 2026 - Free Commercial Pilot License Practice Questions and Study Guide

High air velocity through the carburetor venturi primarily causes heat loss by vaporization of fuel. This phenomenon occurs because as the air flows rapidly through the narrow section of the venturi, the pressure drops, leading to a decrease in temperature. When fuel is introduced into this low-pressure area, it vaporizes more readily, absorbing heat from the surrounding air, which can result in a cooling effect.

This cooling of the mixture is significant because it directly relates to the efficiency of the carburetor in mixing fuel with air. While this vaporization is crucial for efficient combustion, it also underscores the importance of maintaining proper air-fuel mixtures and can lead to condensation or other issues if not managed appropriately. Understanding the dynamics of air velocity and its effects on fuel behavior is essential for pilots when considering engine performance and potential carburetor icing scenarios.

While other factors such as engine efficiency, fuel flow, and carb ice risk are indeed influenced by airflow and operational conditions, they do not directly connect to the specific impact of high air velocity in the venturi as the loss of heat through vaporization does.