FAA Aviation Mechanic Powerplant (AMP)PropellersEasy
A technician is inspecting a propeller assembly and notes a streamlined fairing covering the hub at the front of the propeller. What is the primary purpose of this component?
- ATo act as the primary structural mounting point for the blades
- BTo house the governor flyweights during operation
- CTo reduce aerodynamic drag and improve airflow around the hub
- DTo provide counterweight action for pitch change
Show answer & explanationAnswer & explanation
Correct answer: C. To reduce aerodynamic drag and improve airflow around the hub
The spinner is a streamlined dome that fairs over the propeller hub and pitch change mechanism, reducing drag and often directing cooling airflow into the engine.
Why the other options are wrong
- A. Blades attach to the hub, not the spinner.
- B. Governor flyweights are inside the governor housing, not the spinner.
- D. Counterweights are separate components, not the spinner.
Propeller Spinner
A streamlined dome-shaped fairing covering the propeller hub to reduce drag and improve airflow.
- Reduces aerodynamic drag
- May direct cooling air to the engine
- Can be a two-piece or one-piece design
Memory trick: Spinner smooths the storm of air