During heavy rain and takeoff, the igniters in a gas turbine engine are designed to operate with what characteristic?

• A. High energy high output
• B. Low energy high output
• C. High energy low output
• D. Low energy low output

Answer: (B)

The ignition system is designed to create a very intense spark in a very short moment. In heavy rain, droplets can absorb heat and quench a flame, so the spark needs to be powerful enough to ionize the air and ignite the fuel-air mixture quickly, but it should come from a relatively small amount of stored energy. That means a low energy source delivering a brief, high-output pulse that produces a hot, high-temperature plasma at the spark gap. The result is reliable ignition during takeoff without excessive energy consumption or prolonged heating of the electrodes. If the spark were high energy and long-lasting, it would waste energy, increase wear, and be less reliable in wet conditions. If it were low energy and low output, ignition would be inconsistent in rain.