Main role of HALE UAV(High Altitude Long Endurance Unmanned Air Vehicle) is to provide surveillance, remote sensing and communication relay capabilities for both military and civilian applications. Typically, HALE UAV observes the specific area of interest, travelling at low speed without risk of loss of life at a lower altitude satellite. This development of HALE UAV must be based on the lightweight/flexible structure design technology and composite materials. Airframe structural point of view, weight reduction of the airframe structure is the most important method to improve the flight efficiency. High modulus CRFP(Carbon Fiber Reinforced Polymer) has been used in designing the structure in order to minimize the airframe weight. With respect to structural design and analysis, the key question is to decide an adequate airworthiness certification based on defining suitable load cases for sizing of various structural components. In this study, MSC/FlightLoads is introduced to analyze the flight loads for the HALE UAV. The MSC/FlightLoads can compute the flexible air load and analyzed loads are distributed on structural model directly. A preliminary structural concept is defined in accordance with the estimated inertial and aerodynamic loads. A FEM analysis was carried out using the MSC/Nastran code to predict the static behaviour of UAV structure.