FAA Powerplant Written Practice Test 2026 – Complete Exam Prep

The function of the inlet guide vane assembly on an axial-flow compressor is to direct air onto the first stage rotor blades at the proper angle. This is crucial for maintaining efficient airflow through the compressor and ensuring that the air is introduced to the rotor blades in a manner that optimizes performance. Proper alignment of the airflow not only minimizes turbulence but also helps in maximizing the pressure rise across the compressor stages.

The inlet guide vanes can be adjusted, allowing for changes in the angle of attack of the incoming air, which is especially beneficial during various operating conditions, such as varying engine speeds. By ensuring that the air enters the rotor blades correctly, the compressor can achieve better performance, reliability, and efficiency, as the proper angle of attack is essential for the effective conversion of kinetic energy from the rotor blades.

While other options mention aspects related to performance and efficiency, such as reducing drag and enhancing overall compressor performance, they do not directly describe the specific mechanical function of the inlet guide vane assembly like directing air flow does.