FAA Ground School Practice Test

What is one procedure a pilot can perform to assist an overheating engine?

1. Reduce altitude rapidly

2. Enrichen the fuel mixture

3. Close the carburetor heat

4. Increase propeller RPM

The correct answer is: Enrichen the fuel mixture

Enrichening the fuel mixture is a procedure that can assist an overheating engine. This action increases the ratio of fuel to air in the engine. When an engine is running too hot, adjusting the mixture to a richer setting helps cool it down by providing more fuel, which has a cooling effect as it evaporates. The additional fuel also can aid in preventing the engine from detonation, which can occur when temperatures are excessively high. Other procedures, although they may seem like plausible responses to an overheating engine, do not address the primary need for cooling as effectively as enriching the fuel mixture does. Rapidly reducing altitude might lead to increased airflow over the engine, but it doesn't specifically address the fuel-air mixture issue. Closing carburetor heat may not have a significant impact on cooling, as carburetor heat is typically used to prevent icing rather than to reduce engine temperature. Increasing propeller RPM can enhance the engine's cooling as a side effect of increased airflow, but it does not directly solve the problem of an overheated engine.