FAA Powerplant Written Practice Test

Which of the following is a characteristic of a thrust bearing used in most radial engines?

1. Flat design

2. Deep-grooved ball

3. This design is non-adjustable

4. Made from composite materials

The correct answer is: Deep-grooved ball

Thrust bearings in most radial engines are designed to accommodate axial loads while allowing for smooth rotational motion. The deep-grooved ball design is particularly effective for this purpose because it can handle thrust in both directions and manage radial loads. The deep grooves in the bearing allow for higher load capacity and improved stability, ensuring that the bearing can withstand the stresses of engine operation without significant wear. In addition to this structural capability, deep-grooved ball bearings often allow for better alignment and can compensate for misalignment, which is important in engines where vibration and changes in load are common. This design contributes to longevity and reliability, making it a preferred choice for thrust applications in radial engines. The other options either lack the structural benefits necessary for thrust applications in radial engines or do not accurately describe common characteristics of thrust bearings utilized in this specific context.