2 What is propeller? Consists of two or more blades Rotating wing Transforms the rotary power of the engine into forward thrust
3 The Left Turning Tendency The propeller causes the airplane to turn left.Four major causes areTorqueCorkscrew effect (Slipstream effect)Asymmetric loading of the propeller (P-Factor)Gyroscopic effect
4 Torque Reaction Newton’s Third Law of Physics For every action, there is an equal and opposite reactionWhen the airplane is in the air, this force is acting around the longitudinal axis, tending to make the aircraft roll to the leftWhen the airplane is on the ground during takeoff, torque will cause the airplane to yaw to the left.
5 Corkscrew EffectAt high propeller speeds and low forward speed, this spiraling rotation is very compact and exerts a strong sideward force on the aircraft’s vertical tail surfaceIt yaws the airplane to the left
6 Asymmetric Loading (P-Factor) It is caused when one side of the propeller produces more thrust than the other sideAt a high AOA, the downward moving blade has a higher resultant velocity, creating more lift than the upward moving bladeIt yaws the airplane to the left
7 Gyroscopic Effect Less noticeable than other three Produces a left yawing motion when pitching down and a right yawing motion when pitching up
8 Summary Propeller = Rotating Wing Torque – rolls and yaws to the left Corkscrew effect – yaws to the leftP-Factor – yaws to the leftGyroscopic EffectYaws to the left when pitching downYaws to the right when pitching up