In this study, we introduce a computational fluid dynamics (CFD) simulations campaign to analyze the forces and moments generated by a fixed-pitch propeller under longitudinal, transversal, and combined flow conditions, utilizing Ansys Fluent. The CFD model is then integrated into the Simulink flight simulator of a lightweight copter-plane unmanned aerial vehicle (UAV). Subsequently, a preliminary Linear Quadratic Integral (LQI) control strategy is developed in MATLAB to optimize trajectory during transitional maneuvers from copter to plane mode.