In order to reduce carbon dioxide emissions, new technologies are being sought in commercial aviation. The top-level objective of the Investigation and Maturation of Technologies for Hybrid Electric Propulsion project (IMOTHEP https://www.imothep-project.eu/ ) is to assess the potential offered by hybrid electric propulsion (HEP). The goal is also to build the corresponding aviation sector-wide roadmap for the maturation of the concepts. The four aircraft concepts are focused on regional and short-to-medium-range aircraft missions (Fig. 24.1). Small/medium-range (SMR) conservative is based on existing Airbus A320. Turbo-electric propulsion consists of two gas turbines driving generators that power electric motors distributed along the wing. SMR radical with a turbo-electric drive is designed using an innovative tailless system, with the fuselage partially serving as a wing. Regional conservative is based on ATR-42-600 construction. The propulsion is integrated using a parallel hybrid power plant system that consists of two gas turbine engines, generators, and electric motors. Regional radical is also based on ATR-42. Series/parallel partial hybrid electric consists of one gas turbine engine that drives a fan and generator. Distributed fans are driven by electric motors that are powered by the generator and/or batteries. This chapter presents an overview of four hybrid aircraft concepts and simplified wing structure geometry, proposed for the regional radical version. Examples of strength calculations for the wing structure for the critical load case are also presented.