The Chungbuk UAM, a Lift & Cruise type Urban Air Mobility vehicle, is designed primarily for operation in Chungcheongbuk-do. In wind tunnel testing, the Chungbuk type UAM exhibited unstable directional stability, a component of static stability. This instability was believed to be due to the vortex generated by the canard wing and pod, which submerges the vertical tail wing and diminishes the rudder effect, leading to unstable directional stability. To mitigate this issue, ventral fins were installed, and a comparative analysis was performed to evaluate the impact of the ventral fins’ presence. The optimal configuration of the ventral fins were determined by analyzing the angle between the fins. This study also involved an aerodynamic analysis and comparison of static before and after increasing the area of he vertical tail, aiming to enhance directional stability.