FAA Powerplant Written Practice Test

What is a correct statement about the ignition system of a turbine engine?

1. The system is activated during startup

2. The system is normally energized during operation

3. The system is normally de-energized after startup

4. The system operates continuously regardless of engine state

The correct answer is: The system is normally de-energized after startup

In a turbine engine, the ignition system plays a critical role during the startup phase when the engine requires an ignition source to initiate the combustion process. After successful engine startup, once the engine reaches a certain speed and stable operation is confirmed, the ignition system is typically de-energized. This is because the sustained combustion processes are maintained by the fuel-air mixture and the high temperatures generated within the engine, negating the need for continuous ignition. The correct assertion about the ignition system being normally de-energized after startup reflects this operational characteristic. Once the engine has lit and is running efficiently, the ignition system is not needed to continue functioning, which enhances reliability and reduces unnecessary strain on the system components. Proper understanding of this operational logic is essential for troubleshooting and maintenance protocols in turbine engines.