The paper aims to present the phases and the achievements of the aerodynamic design activities carried out on a box-wing aircraft, called PrandtlPlane, proposed as a sustainable solution for the fulfilment of the more and more demanding requirements of the fast-growing air transport. The activities here presented are included in the on-going Project PARSIFAL (“Prandtlplane ARchitecture for the Sustainable Improvement of Future AirpLanes”), funded by European Union under the Horizon2020 Program. Starting from the conceptual aerodynamic design of the PrandtlPlane architecture, the paper follows the development of the aerodynamic design, dealing with the preliminary definition of a reference configuration, which performances have been evaluated with both low and high fidelity tools, and the optimization procedure for the improvement of cruise performance
