Definition
A streamlined, cone-shaped fairing fitted over the propeller hub that smooths airflow into the engine cowling and gives the propeller its characteristic pointed front profile.
Plain English
The smooth, cone-shaped cover at the very front of a propeller, where the blades meet the hub. It tidies up the airflow and finishes off the nose of the aircraft.
Context Anchor
Seen during preflight inspection at the nose of many propeller-driven airplanes.
Derivation
Spinner comes from the verb “spin,” meaning to turn around. The name fits because the part is mounted with the propeller assembly and turns with it, even though its job is mainly to cover and smooth the front of the propeller hub.
Why Pilots Care
A cracked or loose spinner can create dangerous vibration, imbalance, or even separate in flight, directly affecting safety and propeller operation.
Analogy
A spinner is like a smooth cap on the front of a fan. The fan blades still do the work, but the cap covers the center and gives the front a cleaner shape.
Intuition Check
Do not confuse the spinner with the propeller blades. The spinner is the cover at the center; the propeller blades are the parts that produce thrust.
Example Sentence 1
During preflight, she checked the spinner for cracks and made sure it was firmly attached to the propeller hub.
Example Sentence 2
Replacing the damaged spinner reduced drag and smoothed the airflow into the engine.