Originally posted by Wings
OOOh Boy...Here is my twist
On an airplane I generally think of torque as the adverse yaw effect caused from increasing or decreasing the prop speed.
Adverse yaw has nothing to do with engine torque, it happens even in gliders. Adverse yaw is the tendency for the airframe to YAW in the opposite direction of the roll input. Roll the wings right the fuselage yaws left. The force you are reffering to is called "P" factor and is caused by the combination of asymetric thrust and the fact that the air from a prop doesn't go straight back, it rotates sorta like a tornado on its side.
The only thing that rotates a plane in hover is the amount of torque used by the prop to produce the thrust needed. Change the needed torque and you changed the rotational force.
