FAA Powerplant Written Practice Test

What should be done when mounting a replacement engine?

1. Use any available bolts

2. Install manufacturer specified bolts and torque them to the recommended value

3. Reuse original bolts regardless of condition

4. Utilize standard torque values regardless of manufacturer

The correct answer is: Install manufacturer specified bolts and torque them to the recommended value

When mounting a replacement engine, it is crucial to install manufacturer-specified bolts and torque them to the recommended value. This practice ensures structural integrity and safety of the engine installation. The manufacturers design their engines with specific hardware in mind, which includes particular bolts that are suited for the specific stresses and operational characteristics of that engine. Using the correct bolts provided by the manufacturer ensures that the material and strength of the fasteners are appropriate and that they will perform as intended under operating conditions. Torquing these bolts to the manufacturer-specified values is equally important, as it allows for even distribution of stress across the engine assembly and prevents issues such as loosening or over-tightening, both of which could lead to catastrophic engine failure. The alternative choices present practices that can significantly compromise safety and performance. For instance, using any available bolts disregards the specific requirements for the engine and could result in inadequate securing of critical components. Similarly, reusing original bolts without assessing their condition can lead to the risk of failure if those bolts are fatigued or damaged. Lastly, utilizing standard torque values without regard to manufacturer specifications ignores the unique engineering design of each specific engine application. This could potentially lead to improper clamping forces and subsequent engine failure.