An unmanned aerial vehicle (UAV) is designed for low-speed, low altitude, long endurance missions typical to UAVs of this size and class. The UAV structure is configured to be substantially impervious to small arms fire and to have a very small representative radar cross-section. The UAV is modular such that the main wings and tail wing assembly are quickly and easily, detached from the fuselage for ease of transport and to provide an airframe that is quickly and easily adapted to any particular mission.