This book deals with the development of an airfoil for an unmanned aerial vehicle (UAV) with internal blowing propulsion system. This development is based on the modification of a selected airfoil from the NACA four-digit family. The modification of this airfoil was made in order to create a blowing outlet on the suction surface. Therefore, four different locations along the chord line for this blowing outlet were analyzed. This analysis involved the aerodynamic performance which meant obtaining the lift, drag and pitching moment coefficients experimentally by means of wind tunnel tests and also numerically by means of computational fluid dynamics (CFD). The methodology to obtain the forces experimentally was through an aerodynamic wire balance which was also developed in this investigation. Another important aspect in this book is the collection of the fluid flow pattern by means of CFD and experimental visualization techniques such as oil and smoke. The experimental and numerical results were found to be in excellent agreement. Finally, a selection of the airfoil with the best aerodynamic performance is made.