FAA Powerplant Written Practice Test

What type of ignition system is used in the majority of small, light sport aircraft engines?

1. Magneto ignition systems

2. Breaker-less capacitor discharge ignition systems

3. Conventional battery ignition systems

4. High tension ignition systems

The correct answer is: Breaker-less capacitor discharge ignition systems

The majority of small, light sport aircraft engines utilize breaker-less capacitor discharge ignition (CDI) systems due to their efficiency, reliability, and lower maintenance requirements. This type of ignition system involves using a capacitor to store energy, which is then released through the ignition coil to produce a high-voltage spark at the spark plugs. CDI systems are advantageous in smaller aircraft because they provide a strong and consistent spark, which enhances combustion efficiency and helps ensure smoother engine operation. Unlike conventional ignition systems that may require points and periodic adjustments, breaker-less systems reduce the need for maintenance, which is particularly beneficial for light sport aircraft that may prioritize ease of operation and lower upkeep costs. In contrast, magneto ignition systems, while common, typically require more maintenance and can be more complicated to troubleshoot. Conventional battery systems may not be as prevalent in light sport applications due to their increased weight and complexity. High-tension ignition systems, which are often used in larger or more complex aircraft, may not be necessary for the simpler engines found in light sport aircraft. These factors collectively highlight why breaker-less capacitor discharge ignition systems are the preferred choice in this category.