Electrified aircraft are a promising solution to reduce aviation’s carbon footprint across general and commercial aviation sectors. However, existing computational tools for aircraft design require information about the aircraft’s configuration, forcing the designer to down-select before optimizing their design. As a result of the limited flexibility, suboptimal system architectures may be selected during the early phases of conceptual design. To address this, the Future Aircraft Sizing Tool (FAST), an open-source, MATLAB-based tool, was developed as a propulsion system-agnostic tool for early-phase conceptual design. Using limited design parameters, FAST facilitates rapid and comprehensive aircraft sizing and performance evaluation, utilizing an extensive database of over 450 historical aircraft. Both data-driven and physics-based models are combined to seamlessly integrate new electrification technologies into a design while rapidly predicting its performance. This capability enables early-stage design space exploration to rigorously assess a wide range of propulsion architectures, energy sources, and operational strategies for novel aircraft configurations. This paper presents the key features of FAST, including workflows for aircraft sizing and analysis. The paper also presents a case study involving a commercial freighter, demonstrating FAST’s ability to perform design space exploration and early-phase trade studies.

This study evaluates the feasibility and benefits of introducing battery-powered hybrid electric aircraft (HEA) into regional airline operations. Using 2019 U.S. domestic flight data, the ERJ175LR is selected as a representative aircraft, and several HEA variants are designed to match its mission profile under different battery technologies and power management strategies. These configurations are then tested across over 800 actual daily flight sequences flown by a regional airline. The results show that well-designed HEA can achieve 3–7% fuel savings compared to conventional aircraft, with several variants able to complete all scheduled missions without disrupting turnaround times. These findings suggest that HEA can be integrated into today’s airline operations, particularly for short-haul routes, without the need for major infrastructure or scheduling changes, and highlight opportunities for future co-optimization of aircraft design and operations.