Definition
An aerodynamic and inertial force acting on a rotating propeller blade that tends to twist the blade toward a lower (flatter) pitch angle. It is caused by the centrifugal force on each blade element trying to align the blade in the plane of rotation, opposing the aerodynamic twisting force which tries to increase pitch.
Plain English
When a propeller spins, the spinning motion tries to flatten each blade — twisting it toward a lower pitch. That twisting effect is centrifugal twisting force.
Context Anchor
Seen in propeller theory, constant-speed propeller operation, and powerplant maintenance discussions about forces acting on propeller blades.
Derivation
Centrifugal comes from Latin centrum (center) and fugere (to flee) — literally 'fleeing the center.' The spinning blade's mass wants to fly outward in a straight line, and that outward pull is what twists the blade flat.
Why Pilots Care
It is one of the primary forces the propeller governor must overcome to hold a selected RPM.
Grounding Statement
Picture a propeller blade spinning fast enough that its own mass tries to pull outward and twist the blade flatter.
Intuition Check
CTF is not engine torque twisting the whole propeller. It is the spinning blade’s own tendency to twist around its lengthwise axis.
Example Sentence 1
Centrifugal twisting force tends to rotate the propeller blades toward a lower pitch angle as RPM increases.
Example Sentence 2
The constant-speed unit must produce enough oil pressure to overcome centrifugal twisting force and hold the blades at the commanded angle.