Definition
Fitted with weights positioned so that centrifugal force, generated as the propeller rotates, acts to move the propeller blades toward a higher pitch (coarser) angle. On feathering propellers, these counterweights provide the force that drives the blades toward the feathered position when oil pressure is reduced or lost.
Plain English
The propeller has small weights attached to it. As the propeller spins, those weights are flung outward, and that outward pull is used to twist the blades into a steeper angle on their own — without needing oil pressure to do it.
Context Anchor
Seen in descriptions of feathering propellers, especially when explaining how blade angle changes after oil pressure drops or an engine is shut down.
Derivation
From 'counter-' (against, opposing) plus 'weight.' A counterweight is a weight placed to oppose or balance another force. On a propeller, the counterweights oppose the forces that would otherwise twist the blades toward flat pitch, so when something fails, the blades move the other way — toward coarse pitch or feather.
Why Pilots Care
This design allows reliable feathering even if oil pressure is lost, reducing drag after engine failure.
Intuition Check
Counterweighted does not simply mean “heavier” or “balanced.” Here it means fitted with weights that actively help move the propeller blades as the propeller spins.
Example Sentence 1
Because the propeller is counterweighted, a loss of oil pressure allows the blades to move toward the feathered position.
Example Sentence 2
The pilot confirmed the counterweighted propeller had feathered before securing the engine.