This paper explores the design spaces of a thin-haul and a regional aircraft with parallel hybrid-electric propulsion architectures for a 2030 entry into service date. Notional technology reference aircraft models were developed for a 19- and a 50-passenger aircraft based on publicly available data on Beechcraft 1900D and ATR 42-600, respectively. A set of airframe and propulsion system technologies projected to reach maturity by 2030 was infused into the aircraft models. Parametric, physics-based models were created for the charge-depleting hybrid architecture. Different modes of operation were identified and parameterized with a range of design variables to investigate the feasibility and trade space for peak power shaving, climb power boosting, electric taxi, battery usage schedules, and in-flight battery recharge strategies. Thousands of electrified aircraft concepts with varying electrification, operation, and technology scenarios were sized under the same system-level requirements as their conventional counterpart. The resulting multidisciplinary design space exploration environment was used to identify the optimum vision system designs and modes of operation for the minimum block fuel-burn objective. It has been found that both vehicle classes with the charge-depleting parallel hybrid electric architecture provided fuel-burn benefits over their 2030 advanced technology counterparts under certain operational modes.

This study presents a comprehensive analysis of historical trends and future projections for key performance parameters (KPPs) in commercial turbofan aircraft, focusing on operational empty weight to maximum takeoff weight ratio (OEW/MTOW), thrust-to-weight ratio (T/W), thrust-specific fuel consumption (TSFC), and lift-to-drag ratio (L/D). Leveraging the open-source FAST Aerobase, comprising over 400 commercial airframes and 200 engines, drawn from authoritative sources such as FAA and EASA certifications, along with enhanced regression modeling, this study systematically examines the evolution of each KPP in response to technological advancements, market demands, and regulatory constraints. The analysis reveals that TSFC improvements align closely with technological advances and primarily increases in bypass ratio enabled by core downsizing. Trends in OEW/MTOW and T/W are dominated by market-driven range, size, and regulatory factors rather than pure material or propulsion breakthroughs, which indicates limited room for further improvement without disruptive configurations. Cruise L/D improvements have been primarily enabled by wingtip devices, although they are approaching structural and regulatory limits. This work lays a robust foundation for the open-source Future Aircraft Sizing Tool (FAST), equipping designers with data-driven insights to support early-stage design decisions and providing a transparent resource for understanding the historical and technical drivers of commercial aircraft performance.

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 paper presents a novel methodology for predicting key aircraft design parameters using Gaussian process regressions (GPRs) applied to a comprehensive, open-source database of over 400 aircraft and 200 engines. The database, made freely available through the Future Aircraft Sizing Tool (FAST), enables aircraft designers to apply detailed historical data in early-stage conceptual design and provides full visibility into the data underlying the regressions—unlike traditional regression models, where the training data and model fit are often not disclosed. The nonparametric GPR models developed in this work allow for flexible input configurations, improving the accuracy of predicting critical parameters, such as operating empty weight and uninstalled engine weight, compared to established regressions from the literature. By incorporating a broader range of inputs, these models reduce prediction errors and provide tighter error distributions, leading to more reliable estimates during early design phases. This paper outlines a methodology for adapting conventional aircraft data to explore hybrid-electric and fully electric aircraft designs, ensuring that historical data can be leveraged effectively for novel propulsion systems. Additionally, the flexibility of the GPR framework allows users to create their own regressions and update predictions as new data becomes available, making it a useful tool for researchers working with their own datasets.

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.