Preliminary design of a Tiltwing UAV with a box wing configuration

In the last years, aircraft disruptive configurations have been studied on view to increase civil air transport and safety of flight and, also, to reduce air pollution and noise. One of the promising configurations is the so called box wing, based on the Best Wing System concept by L. Prandtl. This paper presents an application of the box wing to the case of an unconventional Unmanned Air Vehicle (UAV), called "TiltOne", because the two horizontal wings tilt together with the engine-propeller groups, so allowing us to take off and landing vertically and to fly as a fixed wing airplane during cruise. TiltOne is full electric, with distributed propulsion; the preliminary design has been carried out by using a home-made optimization code, where aerodynamics, controls and electric propulsion are taken into account. After defining the airframe configuration, aerodynamic analyses have been performed, electric motors and propellers and batteries are defined; finally, a detailed analysis of the mechanical components is presented and a prototype has been manufactured. Preliminary vertical test flight has been carried out successfully.