The first indication of induction icing is usually a _____. If suspected, what action should be taken?

The first indication of induction icing is typically a reduction in engine RPM or manifold pressure (MP). This reduction occurs because ice builds up in the induction system, obstructing airflow and causing the engine to run less efficiently. When this issue is suspected, applying full carburetor heat is the appropriate action to take. Carburetor heat works by introducing warmer air into the carburetor, which helps to melt any ice that might have formed, improving performance and potentially preventing engine failure due to icing.

This action is critical because if induction icing is not addressed, it can lead to significant power loss or even engine shutdown. Recognizing the symptoms of induction icing early and responding by applying carburetor heat can effectively mitigate the situation, maintaining engine performance and ensuring safety.