FAA Powerplant Written Practice Test

What is a common sign of bearing failure in an engine?

1. Unusual engine noise

2. Increased fuel efficiency

3. Vibration in the control column

4. Excessive oil pressure

The correct answer is: Unusual engine noise

A common sign of bearing failure in an engine is unusual engine noise. This abnormal noise often arises from improper lubrication or damage to the bearing surfaces, leading to metal-to-metal contact. The failure of bearings can manifest in various ways, such as a knocking or grinding sound that indicates wear or other issues within the engine. Unusual engine noises serve as an early warning signal that something is amiss and should prompt further investigation. Other indicators of potential bearing failure can include changes in vibration patterns and fluctuations in oil pressure; however, unusual engine noise is one of the most immediate and easily recognizable signs. Increased fuel efficiency is not associated with bearing failure and would generally indicate optimal engine performance. Vibration in the control column may suggest other issues like imbalance or misalignment but is not a specific sign of bearing failure. Excessive oil pressure could be due to various factors unrelated to bearing condition, such as a malfunctioning pressure relief valve, making it an unreliable indicator on its own for bearing issues.