Definition
A streamlined, cone- or dome-shaped fairing fitted over the propeller hub at the front of the engine. It smooths airflow into the engine cowling and covers the hub and attaching hardware.
Plain English
The smooth, pointed cap on the very front of the airplane that spins with the propeller. It hides the centre of the propeller and helps air flow neatly back into the engine.
Context Anchor
Seen during preflight inspection and in discussions of the engine and propeller area.
Derivation
‘Spinner’ simply describes what it does — it spins with the propeller. The aviation term keeps the everyday meaning, applied to this specific part.
Why Pilots Care
It improves cruise efficiency by cutting drag and shields the hub from impacts that could lead to vibration or blade imbalance.
Analogy
A propeller spinner is a little like a smooth hubcap for the propeller: it covers the center area and gives the front a cleaner shape.
Intuition Check
Do not confuse the propeller spinner with the propeller blades. The blades make thrust; the spinner is the cover over the center area.
Example Sentence 1
During preflight, the pilot checked the propeller spinner for cracks and made sure its mounting screws were tight.
Example Sentence 2
Replacing a damaged propeller spinner restored the airplane's normal cruise performance.