The present document is a deliverable (D3.1) of Work Package 3 “Models and simulations for airframe and propulsion integration” within the EU funded project INDIGO: INtegration and Digital demonstration of low-emission aIrcraft technoloGies and airport Operations.Since INDIGO incorporates various coupled multidisciplinary tools, there is a need of having a central dataset encompassing the initial aircraft geometry as well as the most significant results emanating from the diverse analysis tools. The storing of these parameters will facilitate the estimation of mass distribution arising from the design of the airframe, the installation of the engine, and the electric powertrain architecture. Moreover, they will contribute to the establishment of a singular, comprehensive definition of the aircraft structure. To accomplish this objective, it was decided to define both geometry, airframe and propulsive system for the DHEP-LARW concept using a CPACS format.In light of the aforementioned, this document is structured as follows: the first section, after a brief introduction, is dedicated to succinctly describe general concepts utilized across the CPACS data exchange format; subsequently, there is a dedicated section that provides a description of the CPACS structure employed, emphasizing specific parameters which were appended to the current CPACS version.