FAA Powerplant Written Practice Test

How can the effectiveness of a magneto installation be verified?

1. By testing ignition wires

2. By using a timing disk

3. By checking the spark plug condition

4. By measuring piston travel

The correct answer is: By using a timing disk

Using a timing disk to verify the effectiveness of a magneto installation is a common and reliable practice in aviation maintenance. The timing disk allows technicians to accurately check the timing of the ignition system, ensuring that the magneto sparks at the correct moment before the piston reaches top dead center (TDC) on the compression stroke. Proper timing is critical for optimal engine performance, as it directly affects engine power and efficiency. The timing disk method involves attaching the disk to the engine's crankshaft, which enables maintenance personnel to observe the points at which the magneto produces a spark in relation to the crankshaft position. This ensures that the ignition system is correctly timed, which is essential for the smooth operation of the engine during flight. The other options may relate to the ignition system or engine health, but they do not specifically address the timing aspect of magneto effectiveness. Testing ignition wires may provide insight into the electrical continuity and resistance but does not verify timing. Checking spark plug condition can indicate the health of the ignition system but is not a direct measure of magneto functionality. Measuring piston travel usually pertains to engine mechanics rather than the operation of the ignition system. Thus, using a timing disk specifically targets the assessment of magneto performance with respect to ignition timing,