All buoyant and hybrid buoyant aerial vehicles have directional stability issues at low speed. Electric
trimmers are one of the potential solutions for controlling the yaw motion of such vehicles in which
partial lift is obtained from the wings. However, available propeller disk area of such trimmers is limited
due to small surface area of the vertical tail. In the present work, maximum input power required by thin
electric propellers with different pitch values are compared to obtain an optimised value of pitch for
propeller selection. Analytical as well as computational techniques are employed to evaluate the moment
generated by tangential thrust produced by a ducted propeller. Motocalc® software under predicts the
thrust value when compared with the computational results under the same flow conditions. The estimated
yaw force produced by the propeller is quite significant and it can also be used for creating differential
thrust using twin electric motors.