In the context of reducing the environmental footprint of tomorrow’s aviation, Distributed Electric Propulsion (DEP) has become an increasingly interesting concept. With the strong coupling between disciplines that this technology brings forth, multiple benefits are expected for the overall aircraft design. These interests have been observed not only in the aerodynamic properties of the aircraft but also in the structural design. However, current statistical models used in conceptual design have shown limitations regarding the benefits and challenges coming from these new design trends. As for other methods, they are either not adapted for use in a conceptual design phase or do not cover CS-23 category aircraft. This paper details a semi-analytical methodology compliant with the performance-based certification criteria presented by the European Union Aviation Safety Agency (EASA) to predict the structural mass breakdown of a wing. This makes the method applicable to any aircraft regulated by EASA CS-23. Results have been validated with the conventional twin-engine aircraft Beechcraft 76, the innovative NASA X-57 Maxwell concept using DEP, and the commuter aircraft Beechcraft 1900.

This paper presents FAST-OAD-CS23-HE, an open-source framework that has been developed as an extension of the existing FAST-OAD-GA framework to allow for medium fidelity sizing of hybrid and electric aircraft using component models dependent on operating conditions and sizing criteria. It inherits Overall Aircraft Design methodologies from the original framework and adds a library of models to represent physical components for hybrid powertrains. It also adds a generic methodology that enables the extension to multiphysic simulation for the powertrain and the consideration of synergistic interactions and supports the addition of new components. A graph-based description of the powertrain was chosen to easily describe complex powertrains that could be considered in innovative architectures as well as ease the future interfacing with external tools. In addition to that, the graph-based approach allows the automation of the construction of the design problem, which removes the need for users to handle complex scripts. It has been developed after a comparison of existing methodologies and open-source framework in an effort to bridge the gap in terms of preliminary design of electric aircraft. With the models implemented with the default delivery of the code, two aircraft were studied to serve as a reference to showcase the capabilities of this framework.