10 through a common transmission and rotate at a certain ratio to each other for example the tail rotor 55 may rotate five times for every one time the main rotor 45 rotates as the engine of the helicopter 10 rotates the main rotor 45 in one direction torque is created causing the fuselage 15 to rotate in the opposite direction the rotation of the tail rotor 55 creates a thrust that counteracts the torque that the main rotor 45 produces thereby allowing the helicopter 10 to maintain its heading and provide yaw control yaw is controlled by changing the pitch of the tail rotor 55 thereby controlling thrust the pitch of tail rotor 55 is controlled by right and left rudder pedals schematic representation of these pedals can be seen in fig4 to turn the nose of the helicopter right for example depressing the right rudder pedal decreases the pitch of the tail rotor 55 thereby reducing thrust and the torque then turns the helicopter nose right depressing the left rudder pedal increases the pitch of the tail rotor 55 thereby increasing thrust and turning the nose of the helicopter left a balanced performance between main rotor 45 and tail rotor 55 at normal flight would generally be a neutral position of the right and left rudder pedals the rpm 39 s of the main rotor 45 and the tail rotor 55 are fairly constant for instance if the main rotor 45 is operating at 300 rpm then the tail rotor is operating at approximately 1500 rpm there may be a slight variation in the ratio at which the two rotors operate up to five percent undesirable performance of tail rotor 55 would.