This thematic topic focuses on the design of a 19 passenger commuter aircraft based on alternative propulsion concepts (hybrid/electric) targeting near-zero CO2 emissions. A full design loop is required, evaluating a range of design options, resulting in a mature conceptual design for the selected design. The design should be compliant with the new level 4 FAR23 / CS23 regulation. HECARRUS employs methods suitable for analyzing advanced technologies implemented for propulsion and power generation, and takes full advantage of the latest advances in aerospace, electrification and autonomous technologies in a hybrid-electric propulsion strategy to couple the most efficient turbines with generators providing electric power and recharging batteries in several competent technologies, to cover a broad spectrum of these applications. The ultimate idea of the project will be to design a hybrid-electric system with a power output in the range of 1 MW utilizing two engines (two thermal cores) as the propulsive units of a 19-passenger short haul aircraft. With a focus on the key propulsion sub-systems, aircraft structure and performance that interfaces with existing conceptual design frameworks, this project will aim at full design space exploration of the various hybrid-electric concepts at low TRL level. It is underlined that the technologies described and investigated in view of this proposal are complementary to engine core technologies currently under investigation in other EU projects. In other words, the potential fuel efficiency benefits from HECARRUS can be stackedup to efficiency benefits from other projects as all the technologies gradually mature for entry into service by 2030.