Originally Posted by
Fl1ingfrog
It is much more simple: the term torque is the word we use to describe the rotational or twisting force. The term does not refer to the linear force, when 'Newtons' or 'horse power' is the measurement.
The yaw you describe is partly a gyroscopic effect. The rotating propeller and the helicopter rotor both can be considered as a disc; the bicycle wheel provides a good demonstrator. But the asymmetric thrust from the propeller (the down going blade produces more thrust than the upgoing blade) plus the resulting propeller slipstream acting on the fuselage and empennage, act together to cause the yaw to the left, but with engines rotating to the right. With Engine and propeller assemblies that rotate to the left the result is a yaw to the right.
The increased left yaw when the tail is raised is caused only by gyroscopic precession. The yaw due to asymmetric thrust reduces as the tail is raised, it does not increase.