FAA Powerplant Written Practice Test

What is the primary purpose of stator vanes in the compressor of an axial flow turbine engine?

1. Increase fuel flow

2. Improve engine cooling

3. Increase air pressure

4. Reduce noise levels

The correct answer is: Increase air pressure

The primary purpose of stator vanes in the compressor of an axial flow turbine engine is to increase air pressure. Stator vanes are fixed aerodynamic surfaces that guide the airflow through the compressor stages. As air flows through these vanes, they help direct and accelerate the air to achieve higher velocity before it enters the next stage of the compressor, ultimately leading to an increase in pressure. By effectively manipulating the airflow, the stator vanes ensure that the air is compressed more efficiently, which is essential for maintaining the performance of the engine. This increased pressure then contributes to the combustion process by ensuring that sufficient air is available to mix with the fuel, thereby enhancing thrust production and engine efficiency. The other options presented relate to functions that, while important in different contexts, do not capture the primary role of stator vanes in this specific engine component.