FAA Powerplant Written Practice Test

Where can cooling fins typically be found on air-cooled engines?

1. Around the fuel tank

2. On the engine cowling

3. On cylinder heads and cylinder barrels

4. Inside the engine compartment

The correct answer is: On cylinder heads and cylinder barrels

Cooling fins are typically found on the cylinder heads and cylinder barrels of air-cooled engines to enhance heat dissipation. The primary function of these fins is to increase the surface area exposed to the air, allowing for more efficient cooling as air flows over them during engine operation. This is crucial in maintaining optimal operating temperatures, preventing overheating, and ensuring reliable engine performance. Placement on the cylinder heads and barrels is intentional; these components generate the most heat during combustion and operation. By having fins directly on these parts, it effectively cools the engine without needing an external cooling system like those found in liquid-cooled engines. The other options do not align with the function or location of cooling fins. For instance, cooling fins would not be found around the fuel tank or inside the engine compartment, as those areas do not require the same type of cooling mechanism provided by the fins. In addition, the engine cowling serves to streamline airflow and protect the engine rather than facilitate cooling directly through fins.