The technology of UAV (Unmanned Aerial Vehicle) has been developing since its conception many years ago. UAV has its own advantages such as, computerizing and autonomous without an on-board pilot by using digital and electronic system which manned aircraft don’t have. Therefore, there is no risk of loss of life and it is easier to be maintained than manned aircraft. Nowadays, UAV is widespread and used in industry, military and civil work as it can be controlled remotely or can autonomously complete missions. This book represents how to use CFD in predicting the longitudinal and lateral stability and control characteristics of a full-scale model of ducted fan VTOL UAV at both vertical and horizontal flight. Meanwhile Real-time flight simulation and modeling is discribed by using a linear model linked with MIMO control laws depended on unique aerodynamic characteristics from CFD, wind tunnel testing and theoretical method. These research method mentioned in this book should be useful to professionals in VTOL UAV and Aerospace Engineering, or anyone else who may be interested in analyzing characteristic of air vehicle for design process.