Tail Rotor

The tail rotor contributes primarily to the side force and yawing moment equations of equilibrium. Nevertheless, a complete analysis will also account for small contributions to the other four equations of equilibrium. Figure 8.4 shows the geometric relationships that govern the individual tail rotor forces and moments.

XT = – HT

ZT = bls TT (for tail rotor blade closest to main rotor going up)

ZT = —KSr Tt (f°r tail blade closest to main rotor going down)
MT = —QT (for tail rotor blade closest to main rotor going up)

AfT = Qr (for tail rotor blade closest to main rotor going down)

Once the tail rotor thrust to provide the antitorque forces that the vertical stabilizer does not provide is known, the other tail rotor parameters, bl$, HT, and Qj> can be calculated by the methods of Chapter 3.