Originally Posted by
SASless
Think of the tail rotor much like a constant speed Prop on an airplane....the amount of thrust produced can be varied by changing the pitch of the Prop....or if you leave the Prop Pitch constant....you can alter the thrust produced by changing the RPM.
Assuming the Tail Rotor is turning....and it is a fixed control problem causing the issue....one can vary the RPM by means of the Engine(s) throttle(s).
Collective setting or movement can also affect yaw in that situation by increasing or decreasing the amount of Torque of the Main Rotor produces.
Adding Collective produces more an increase in torque.....and the opposite when Collective is reduced.
Page 11-16 provides the FAA discussion of Tail Rotor Malfunctions.
https://www.faa.gov/sites/faa.gov/fi...k/hfh_ch11.pdf
Nice description. Also it’s worth adding that the thrust is following a ‘square law’ with the rpm. So small rpm variations have a big thrust change.