FAA Powerplant Written Practice Test

What must a piston engine undergo after being overhauled?

1. A complete engine replacement

2. Run-in procedure

3. Electrical system check

4. Fuel system inspection

The correct answer is: Run-in procedure

After a piston engine has been overhauled, it is essential to conduct a run-in procedure. This procedure is critical for several reasons. During the run-in, the engine is operated under specific conditions to allow for proper seating of the piston rings and other components. This helps to ensure that the engine achieves optimal performance and efficiency. The run-in procedure also allows for the identification of any potential issues that may not have been apparent before the overhaul, including oil leaks, overheating, or unusual noises. Monitoring the engine closely during this run-in phase aids in confirming the integrity of the overhaul and ensures that all components are functioning correctly. While a complete engine replacement may seem like an option for a malfunctioning engine, it is not a necessary step after an overhaul if the engine is functioning correctly. Similarly, checks on the electrical system or fuel system are important maintenance tasks but are not required specifically after an overhaul. The run-in process is a key part of the overhaul sequence, ensuring the longevity and reliability of the engine after undergoing such significant maintenance.