How can the presence of carburetor ice be verified in an aircraft with a fixed-pitch propeller?

The verification of carburetor ice in an aircraft equipped with a fixed-pitch propeller can be effectively determined by applying carburetor heat and observing the resulting RPM behavior. When carburetor ice forms, it restricts the airflow to the carburetor, which can result in a decrease in engine power and a corresponding RPM drop.

By applying carburetor heat, the ice begins to melt or sublimate, allowing for better airflow through the carburetor. This process typically results in an initial decrease in RPM due to the warmer air entering, which is less dense than the cooler air. However, once the ice is clear, the engine's power output will increase, leading to a gradual recovery and increase in RPM. This observable change demonstrates the effectiveness of the carburetor heat in addressing the ice blockage, thus confirming its presence.

The other choices do not reliably indicate carburetor icing. Noting a sudden increase in RPM would be confusing because it does not provide clear evidence of ice presence or its removal. Observing a gradual increase in fuel flow does not correlate with symptoms of ice formation in the carburetor. Checking for a decrease in engine temperature lacks specific connection to carburetor ice and can be influenced by various