When experiencing ice blockages, what is a potential corrective action on a CE-172?

Activating the alternate air source is a potential corrective action when experiencing ice blockages in a CE-172. In aircraft equipped with carburetors, ice can form in the carburetor due to the temperature drop and moisture in the air, leading to a loss of engine performance. When ice blocks the airflow into the engine, activating the alternate air source allows the engine to draw air from a less obstructed route, bypassing the blockage and restoring proper airflow. This can help maintain engine performance and reduce the risk of engine failure due to ice blockage.

The other options, while they may be relevant in other contexts, do not specifically address the issue of ice blockages in the carburetor. Reducing throttle settings could potentially worsen the situation by decreasing engine power. Descending immediately may not be advisable if the ice is manageable and clearing the blockage through alternate air is possible. Notifying ATC is important for safety but does not resolve the immediate issue of ice blocking airflow.