FAA Powerplant Written Practice Test

What is a potential symptom of a faulty ignition system in a turbine engine?

1. Increased fuel consumption

2. Hard starting

3. Engine overheating

4. Unstable engine performance

The correct answer is: Unstable engine performance

A faulty ignition system in a turbine engine can lead to unstable engine performance. This is primarily because the ignition system is responsible for initiating the combustion process within the combustion chamber. If the ignition system is malfunctioning, it may not provide a consistent or adequate spark. As a result, the fuel-air mixture may not ignite properly or at the right time, leading to fluctuations in engine power output, irregular RPMs, and overall instability during operation. Instability in engine performance can manifest as surging, sputtering, or even complete engine failure in severe cases. Addressing ignition system issues promptly is crucial to maintain consistent and reliable engine function, ensuring safe operation during flight. Other symptoms, while related to engine performance, do not directly indicate faults strictly linked to the ignition system as clearly as unstable performance does.