Definition
The direction in which a propeller turns as viewed from the pilot's seat looking forward. In most U.S.-built single-engine airplanes, the propeller rotates clockwise from the pilot's perspective. This rotation produces several left-turning tendencies during high-power, low-airspeed conditions such as takeoff and climb, including torque reaction, P-factor, spiraling slipstream, and gyroscopic precession.
Plain English
The way the propeller spins, looked at from the pilot's seat. The direction it spins matters because it makes the airplane want to pull to one side during takeoff and climb, and the pilot has to use rudder to keep the nose straight.
Context Anchor
Encountered when learning how to establish a climb and keep the airplane coordinated and on heading after adding climb power.
Derivation
Propeller comes from the idea of propelling, meaning driving or pushing something forward. Rotation comes from a word meaning to turn in a circle. Together, the phrase points to the spinning part that helps drive the airplane forward.
Why Pilots Care
The direction of spin creates forces that pull the nose left and must be countered with rudder to keep the climb straight.
Intuition Check
Do not think of propeller rotation as only “the propeller spinning.” In flight, that spinning can also affect the airplane’s handling, especially when power is high and speed is low.
Example Sentence 1
Because the propeller rotation in this airplane is clockwise from the pilot's view, the student needed to apply right rudder during the climb to keep the nose straight.
Example Sentence 2
Aircraft with clockwise propeller rotation require different rudder pressure in a climb than those with counterclockwise rotation.