FAA Powerplant Written Practice Test

What unique cooling feature does the Rotax 914 engine have?

1. Air-cooled heads and cylinder barrels

2. Water-cooled heads and air-cooled cylinder barrels

3. Both heads and cylinder barrels are water-cooled

4. No cooling system is employed

The correct answer is: Water-cooled heads and air-cooled cylinder barrels

The Rotax 914 engine features a distinctive cooling system that employs water-cooled heads while utilizing air-cooling for the cylinder barrels. This combination allows for more efficient thermal management of the engine components. Water-cooling is particularly beneficial for the heads because it helps maintain optimal temperatures under various operating conditions, which can lead to better performance and longevity of the engine. Air-cooling of the cylinder barrels, on the other hand, is often sufficient for managing heat due to the high surface area exposed to airflow, which is enhanced during operation in flight. This hybrid approach takes advantage of both cooling methods, capitalizing on their respective strengths. Understanding the cooling features of aircraft engines is crucial for maintenance and ensuring the engine operates within safe temperature ranges, thereby enhancing reliability and performance.