UAM (Urban Air Mobility) aircraft require collision warnings or avoidance maneuvers in urban environments for safety reasons. This study developed a CPA-based automatic collision avoidance system for an LC-type UAM aircraft. The aircraft’s flight control system is configured by integrating SCAS, based on PID control techniques, with SVO and autopilot. For collision avoidance, the autopilot’s automatic collision avoidance module generates avoidance maneuvers based on CPA. These maneuvers are not directly inputted into the autopilot but are processed through the SVO layer to ensure uniform mapping for the UAM aircraft, regardless of the control mode in use. The system’s effectiveness was validated through X-Plane simulations, and four scenarios were defined for UAM operation. The simulation results confirmed the functionality of the automatic collision avoidance system.