Inside civilian applications for Unmanned Aerial Vehicles, the need to place a client sensor or client camera under the wing becomes a specific design being away from the main body of the aircraft. Therefore it is necessary to design a payload bay with some specific requirements: - The distance you need to bring the power supply and the network for communication and control. - The additional moment of inertia of having an object on the wing and their effects on the equations of stability. - The aerodynamic effect that interferes with the original model of the aircraft, producing asymmetry and additional drag in flight. - The natural vibration frequencies of the model and the response to external stimulation. - The manufacturing and maintenance costs. This final bachelor work studies the requirements and designs a possible payload bay implementation in a real UAV of the School. Specifically a camera attached to the Shadow, a large wing span UAV. This will perform a CATIA V5 R17 modeling, aerodynamic study ANSYS FLUENT 13 and dynamic study ANSYS WORKBENCH 13. Some experiments were done in the School's wind-tunnel using a model manufactured by 3D printing technique, made from the geometric model developed in this work.