Optimal models represent an effective approach to addressing airspace congestion issues worldwide. However, their application in Vietnam remains relatively limited. In this research, we focus on applying optimization algorithms to construct the flight trajectory model within the Ho Chi Minh Flight Information Region (HCM FIR). The study aims to propose a solution to the airspace congestion problem, with the first task being to detect and prevent conflicts. By leveraging advanced optimization techniques, we have developed an algorithm to detect conflicts over waypoints, enabling us to manage and analyze the total conflicts within the flight trajectory model built based on the Wind Optimal Track Network (WOTN) model. The output of the algorithm includes suggestions for resolving conflicts by adjusting the aircraft entry time into the system. This algorithm is applied with a view to optimizing routing, scheduling, and airspace utilization while considering various constraints and objectives. The research contributes to the advancement of air traffic management systems, particularly in the context of the HCM FIR, minimizing air traffic controller (ATC) workload, and offering valuable insights for enhancing operational efficiency and safety in the airspace.