FAA Powerplant Written Practice Test

Why is a capacitor-type ignition system predominantly used on turbine engines?

1. Low installation cost

2. Simple maintenance

3. High voltage and high heat intensity spark

4. Lightweight design

The correct answer is: High voltage and high heat intensity spark

A capacitor-type ignition system is predominantly used on turbine engines primarily because it provides a high voltage and high heat intensity spark. This type of ignition system is capable of creating a spark that is strong enough to ignite the fuel-air mixture efficiently, even in the challenging conditions present in turbine engines. The ability to produce a high-energy spark is crucial for reliable engine starting and operation, particularly in high-performance applications where the combustion environment can be quite demanding. In turbine engines, reliable ignition is essential for performance, efficiency, and safety. The high voltage produced by the capacitor-type ignition system ensures that the spark can overcome the ignition energy requirement of fuels, even at high altitudes and low temperatures where the air-fuel mixture can become less combustible. This advantage is especially important in turbine engines, which often operate at higher pressures and may have combustion characteristics that demand more robust ignition sources. Thus, the capability of a capacitor-type ignition system to generate a high voltage, combined with the intense heat of the spark, makes it an ideal choice for the complex operational requirements of turbine engines, ensuring effective engine ignition and overall performance.