Definition
A short, heavy, non-flying propeller used on a reciprocating engine during ground test runs. It absorbs the engine's power and provides cooling airflow but is not designed to produce useful thrust or be flown.
Plain English
A stubby test propeller bolted onto an engine so it can be safely run on the ground without being installed in an aircraft.
Context Anchor
Seen in aircraft maintenance, engine run-in, and ground testing after engine work.
Derivation
Called a 'club' because of its shape — short, thick, and blunt, like a wooden club rather than the long, slender blades of a flight propeller.
Why Pilots Care
A pilot will rarely use a club propeller, but knowing the term helps when reading maintenance records or discussing engine test procedures with mechanics. It also explains why a 'propeller' you see on a test stand looks nothing like one fitted to an aircraft.
Analogy
Think of it like resistance on an exercise bike. The resistance lets the machine work hard in place, without going anywhere.
Intuition Check
Do not read “club” as a flying club or owner group here. In this term, “club” describes the short, heavy test propeller used to load the engine on the ground.
Example Sentence 1
After overhaul, the engine was mounted on a test stand with a club propeller fitted so it could be run up and checked before installation.
Example Sentence 2
Mechanics installed a club propeller on the lightweight trainer for better durability.