Plain English Meaning

The propeller spins one way, so the airplane wants to roll the other way. In most U.S. single-engine airplanes the propeller turns to the right from the pilot's seat, so the airplane tries to roll to the left, and the pilot has to counter that.

Full Definition

The tendency of an airplane's airframe to rotate in the opposite direction to the rotation of its propeller, in accordance with Newton's third law of motion. In a single-engine airplane with a propeller turning clockwise as viewed from the cockpit, torque reaction tries to roll the airframe to the left around its longitudinal axis.

Context Anchor

Seen in discussions of propeller effects, handling, and with in a .