Small unmanned aerial vehicles(UAV) are widely used not only for military applications such as reconnaissance and surveillance but also for leisure activities. The unmanned aerial vehicle’s take-off method includes general land take-off, launch platform take-off without a runway, vertical and hand-launch take-off. In spite of having several advantage, the hand-launching UAV may be somewhat unstable due to possible stall phenomenon during taking-off process depending on the different throwaway movement of a human launcher. Therefore, various damage cases have been occasionally reported from the past operation. In this study, computational fluid dynamics(CFD) method has been used in order to investigate possible safe zone during the hand launch process considering the effect of roll angle and initial take-off speed. Finally, guideline data for a safe hand launching take-off were successfully obtained and presented for the present small UAV model.