Plain English Meaning

A wing-shaped blade that creates lift or pull by spinning. A propeller is the most common example: each blade is shaped like a small wing, and spinning it forward pulls the airplane through the air.

Full Definition

An airfoil that produces lift or thrust by spinning around a central axis rather than by moving forward through the air as a fixed wing does. Propeller blades and helicopter rotor blades are rotating airfoils — each blade has a curved cross-section like a wing, and as it rotates it generates an aerodynamic force perpendicular to its path of motion.

Context Anchor

Seen in propeller and powerplant discussions, where each is treated like a small wing moving in a .