This chapter represents the studies (theoretical, numerical, and experimental) of geometric parameters’ effect on aerodynamic characteristics. Particularly, subchapters consider high-wing and low-wing, wingspan ratio, airfoils and angles of their setting, stagger and vertical gap between the wings, and wings’ dihedral angles. There is research on wingtip devices installed on forward and rear wings that affect not only lift-drag ratio but all three degrees of static stability as well. The chapter includes a CFD study of aerodynamic features of folding design (tube-launched UAV that goes through different sweep angles of the wings immediately after its release). The second edition is complemented by numerical research on aerodynamic loading where specifics for forward and rear wings due to their interference have been found.