The aircraft environmental control system (ECS) is the second-highest fuel consumer system, behind the propulsion system. To reduce fuel consumption, one research direction intends to replace conventional aircraft with more electric aircraft. Thus, new electric architectures have to be designed for each system, such as for the ECS. In this paper, an electric ECS is modeled and then sized and optimized for different sizing scenarios with the aim of minimizing fuel consumption at the aircraft level. For the system and for each component, such as air inlets and heat exchangers, parametric models are developed to allow the prediction of relevant characteristics. These models, developed in order to be adapted to aircraft design issues, are of different types, such as scaling laws and surrogate models. They are then assembled to build a preliminary sizing procedure for the ECS by using a multidisciplinary design analysis and optimization (MDAO) formulation. Results show that the ECS design is highly dependent on the sizing scenario considered. An approach to size the ECS globally with respect to all the sizing scenarios leads to an ECS that accounts for around 200 N of drag, 190 kW of electric power, and 1500 kg of mass for the CeRAS aircraft.

Assessing mitigation strategies for aviation is a critical issue for the aviation stakeholders, while the debate continues on the most appropriate CO₂-equivalence metrics to address non-CO₂ effects. Here, we propose two lightweight climate models that can be parameterised to assess these strategies and move beyond the CO₂-equivalence metrics debate. A first approach relies on the use of the GWP* method, while a second one uses the FaIR climate emulator. These lightweight models, which should be considered as a new family of climate models for aviation that facilitate parametric studies, provide a straightforward and consistent means of evaluating mitigation strategies at the temperature level, although they are still limited for informing policymakers due to the significant uncertainties involved. They bypass the need for CO₂-equivalence metrics for comparing strategies. The latter should rather be used for other applications, such as policy mechanisms to encourage the emergence of strategies, as they are not suitable for assessing temperature changes from aviation. The debate on the choice of CO₂-equivalence metrics could then focus on methodological and ethical criteria. However, this paper demonstrates that the higher the traffic, the more appropriate it is to choose CO₂-equivalence metrics with high values for consistency with temperature estimates.

AeroMAPS is an open-source software, also available as a web application, for performing multidisciplinary assessment of prospective scenarios for air transport. Such investigations are a significant challenge for aviation stakeholders but are required to explore and evaluate different transition strategies for the sector. The framework presented in this paper aims to provide these stakeholders with a standardised methodology for simulating prospective scenarios. Developed using the Python programming language and easy to use via Jupyter Notebooks or graphical user interfaces, it enables the rapid exploration of various decarbonisation strategies for research or decision-making audiences. Several scientific computing packages are used to facilitate the modular assembly of models and solve complex numerical problems. The framework is structured around various models derived from the academic literature and newly developed ones. In particular, it can be used to model various components of the air transport system (air traffic, aircraft fleet, energy carriers), assess its environmental (climate and energy resources) and cost impacts, and perform environmental sustainability analyses. An application is proposed in this paper in order to understand the capabilities, interests and limits of the software. Future developments are planned to improve existing models, complete environmental analyses and continue extending to other disciplinary fields (economics, regulation, sociology), in order to make AeroMAPS a systemic and holistic aviation integrated assessment model.