FAA Powerplant Written Practice Test

Which maintenance activity is crucial for ensuring spark plug reliability?

1. Regular oil changes

2. Maintaining proper gap settings

3. Replacing air filters

4. Cleaning ignition coils

The correct answer is: Maintaining proper gap settings

Maintaining proper gap settings is crucial for ensuring spark plug reliability because the gap between the center and ground electrode directly affects the spark plug's ability to ignite the air-fuel mixture in the engine's combustion chamber. If the gap is too wide, there may not be enough voltage to create a spark, leading to misfires and reduced engine efficiency. Conversely, if the gap is too narrow, it can cause excessive wear on the electrodes and can also lead to incomplete combustion. Therefore, regularly checking and adjusting the spark plug gap as required helps ensure that the spark plugs operate effectively under various engine conditions, promoting reliable engine performance and efficiency. Other maintenance activities, while important for overall engine health, do not directly impact the spark plug's function as significantly as proper gap settings do. Regular oil changes and replacing air filters contribute to engine performance, but they do not directly affect the ignition system. Similarly, cleaning ignition coils can support ignition system performance, but if the spark plugs do not have the correct gap, their reliability will still be compromised.