Professor Alan Mantooth, Distinguished Professor of Electrical Engineering and Computer Science at the University of Arkansas and lead researcher of the UA Power Group, has spearheaded a project that demonstrates the potential of silicon carbide-based motor drives in hybrid electric aircraft. The team recently completed a test flight using a hybrid Cessna 337, equipped with a traditional gas engine in the nose and an experimental electric motor at the rear powered by a silicon carbide inverter. The flight confirmed that silicon carbide (SiC) components can replace conventional silicon-based systems, offering a more compact, lighter, and energy-efficient propulsion solution.
Farnell, C., Corbitt, A., Schwartz, W. G., Faruque, A., Zhao, Y., Huitink, D., Miljkovic, N., & Mantooth, H. A. (2025). Development, Integration, and Flight Testing of a Silicon Carbide Propulsion Drive for a Hybrid Electric Aerospace Application. IEEE Transactions on Power Electronics, 40(12), 18437–18447. https://doi.org/10.1109/TPEL.2025.3597905
Traditional electric motor drives in aircraft rely heavily on silicon-based transistors to control the flow of electricity. While reliable and cost-effective, silicon transistors generate energy loss as heat during switching events and require bulky supporting components such as inductors, transformers, and capacitors. Silicon carbide transistors, on the other hand, can switch significantly faster than silicon devices, reducing energy loss and enabling smaller supporting components. The result is a system that provides similar or greater power in a fraction of the size and weight, a critical advantage in aviation where space and mass are at a premium.
Professor Alan Mantooth, at the University of Arkansas, stated,
“The students got a second-to-none experience. They got to do some hands-on engineering in addition to their scientific work, and they went on and got great jobs”.
Chris Farnell, Assistant Professor of Electrical Engineering and first author on the study, explained the practical implications of this advancement, likening the impact to replacing a large, heavy engine in a race car with something that fits in the palm of your hand while delivering the same performance. This improvement allows aircraft designers to reduce the weight of electrical systems, increase cabin or cargo space, and reduce overall energy consumption for takeoff and cruise.
The test flight of the hybrid Cessna 337 took place in Southern California in 2023. The aircraft demonstrated stable operation of the rear-mounted electric motor using the SiC-based inverter. This flight was a crucial milestone because it verified that the technology works not just in laboratory conditions but in a real-world environment subject to vibrations, mechanical shocks during landing, altitude-related effects, and variations in temperature and humidity.
Designing reliable electric propulsion systems for aircraft presents multiple challenges. Electrical components must withstand vibration, shock, and temperature extremes. In high-altitude environments, dry air increases the risk of partial discharge, which can degrade insulation and affect component longevity. Faster-switching SiC transistors can also increase electromagnetic interference, potentially impacting avionics and other onboard systems. Successfully managing these issues during the flight test demonstrated that the UA Power Group’s design approach is robust enough for operational use.
One of the major benefits of silicon carbide-based motor drives is their reduced size and weight. Smaller components allow for more efficient aircraft design, potentially increasing passenger or cargo space and reducing overall aircraft mass. Lower mass translates to reduced energy consumption during takeoff, climb, and cruise, which is particularly valuable in electric and hybrid-electric aircraft where battery weight is a limiting factor. By reducing component size without sacrificing performance, SiC-based drives provide designers with more flexibility in integrating electrical systems into existing airframes.
While silicon carbide offers performance advantages, it has traditionally been more expensive to produce than silicon. However, as manufacturing techniques improve and component costs decline, the overall system cost can be lower. This is because the smaller supporting components and higher efficiency reduce the total material and cooling requirements for a given power level. Professor Mantooth noted that while silicon is inexpensive, silicon carbide’s higher efficiency and reduced system size can make the total system more cost-effective for applications such as electric aircraft motors.
To further advance silicon carbide technology, the UA Power Group plans to open the Multi-User Silicon Carbide Research and Fabrication Laboratory later this year. This facility will focus on developing smaller, more efficient SiC devices suitable for aerospace and other high-performance applications. The lab will provide a bridge between university research and industrial semiconductor manufacturing, helping to accelerate adoption of SiC technology in hybrid and electric propulsion systems.
The project also serves as a valuable educational experience. Students involved in the project gained hands-on engineering experience in addition to conducting scientific research, preparing them for careers in aerospace, power electronics, and semiconductor industries. Professor Mantooth emphasized that field testing the technology provides insights that laboratory work alone cannot, helping to train the next generation of engineers in both theoretical and applied problem-solving.
This demonstration is part of a growing effort to electrify small and regional aircraft. Silicon carbide-based inverters could become a key technology for hybrid and fully electric planes, enabling lighter, more efficient, and more compact propulsion systems. As aviation seeks to reduce emissions and improve energy efficiency, advances in power electronics like those from the UA Power Group are essential for making electric flight practical.
By integrating high-speed, efficient SiC components into aircraft propulsion, engineers can design electric systems that are not only smaller and lighter but also more energy-efficient and adaptable to various airframe configurations. The success of the hybrid Cessna 337 flight provides a blueprint for future aircraft, demonstrating that silicon carbide technology can meet the mechanical, electrical, and environmental demands of aviation while paving the way for broader adoption in both aerospace and ground transportation sectors.
The University of Arkansas team, led by Professor Alan Mantooth, has demonstrated that silicon carbide-based motor drives can offer substantial advantages over conventional silicon systems for hybrid electric aircraft. The successful flight of the Cessna 337 highlights the potential for lighter, more efficient, and more compact electric propulsion systems, advancing the development of sustainable aviation technologies. This work exemplifies how material innovations in semiconductors can translate into practical engineering solutions, helping to make electric and hybrid flight more feasible and efficient while providing critical experience for students and researchers in the field.
Adrian graduated with a Masters Degree (1st Class Honours) in Chemical Engineering from Chester University along with Harris. His master’s research aimed to develop a standardadised clean water oxygenation transfer procedure to test bubble diffusers that are currently used in the wastewater industry commercial market. He has also undergone placments in both US and China primarely focused within the R&D department and is an associate member of the Institute of Chemical Engineers (IChemE).
