FAA Powerplant Written Practice Test

When using a test run with an overhauled engine, why is a club propeller used?

1. To increase engine RPM

2. For proper cooling and correct load on the engine

3. To reduce drag

4. For enhanced safety measures

The correct answer is: For proper cooling and correct load on the engine

When conducting a test run with an overhauled engine, using a club propeller is primarily beneficial for proper cooling and applying the correct load on the engine. A club propeller is designed to have a relatively low pitch, which helps to ensure that the engine operates within its optimal temperature range during testing. This allows for effective cooling because the lower pitch propeller generates less resistance and thus enables the engine to maintain lower RPMs while still providing sufficient thrust for testing purposes. Furthermore, the correct load is crucial during a test run to simulate real operational conditions without placing excessive strain on the newly overhauled engine. This ensures that the engine can reach and maintain the desired operating parameters without overheating or experiencing undue stress, allowing for a comprehensive assessment of its performance after the overhaul. Overall, using a club propeller aligns with the objectives of validating the engine's functionality while safeguarding its efficient operation and longevity.