FAA Powerplant Written Practice Test

What does the starter of a typical gas turbine engine do until self-accelerating speed is reached?

1. Runs intermittently

2. Continues to crank

3. Automatically shuts off

4. Generates electrical power

The correct answer is: Continues to crank

The starter of a typical gas turbine engine continues to crank the engine until it reaches self-accelerating speed because this is essential for initiating the combustion process. The purpose of the starter is to provide the necessary rotational speed for the engine to reach the point where it can sustain itself through its own combustion. When the starter cranks, it helps the engine to establish the required airflow and compression, allowing fuel to be introduced and ignited. Once the engine reaches self-accelerating speed, the combustion process becomes self-sustaining, and the starter is no longer needed. The role of the starter is thus critical during the initial phase of the engine start-up procedure, ensuring a smooth transition from a non-operational to an operational state. This function directly impacts the successful ignition and overall performance of the gas turbine engine during the starting process.