A hybrid Cessna 337 took flight from a Southern California runway with a unique configuration: a gas engine up front and a rear electric engine powered by a silicon-carbide inverter developed by the UA Power Group. The experiment demonstrated that the silicon carbide system is smaller and more efficient than standard silicon-based motor drives and can replace them in hybrid aircraft.
Alan by Clarence Oxford
Los Angeles CA (SPX) Nov 04, 2025
A hybrid Cessna 337 took flight from a Southern California runway with a unique configuration: a gas engine up front and a rear electric engine powered by a silicon-carbide inverter developed by the UA Power Group. The experiment demonstrated that the silicon carbide system is smaller and more efficient than standard silicon-based motor drives and can replace them in hybrid aircraft.
Alan Mantooth, Distinguished Professor and project lead, stated, "We were the first university to do this for a hybrid electric aircraft. That's a feather in our cap." The successful flight, conducted in 2023, has been documented in the journal IEEE Transactions on Power Electronics. ARPA-E provided funding.
Transistors form the basis of electric circuits by acting as switches or amplifiers. Most modern transistors are silicon-based; silicon is produced from purified sand, making it affordable. Transistors lose energy during state transitions, generating heat. Silicon carbide transistors switch 1,000 times faster, increasing efficiency, and enabling much smaller, lighter components.
Chris Farnell, assistant professor and first author, explained, "Imagine a race car with a big 350 engine that weighs hundreds of pounds. What if you had that same power, but I gave you something that would fit in your hand?"
UA Power Group is recognized in silicon carbide research, but widespread adoption has been hampered by higher costs. "Silicon is made from dirt, and nothing is cheaper than dirt," Mantooth noted. As production costs drop and silicon carbide systems need fewer supporting components, overall system cost decreases. Automotive manufacturers are now showing interest.
Current manufacturing does not yet support nanometer-scale silicon carbide devices for microchips. UA Power Group will open the Multi-User Silicon Carbide Research and Fabrication Laboratory to advance microchip production and foster collaboration between academia and the semiconductor industry.
For aviation, the team built an inverter to convert battery DC into motor AC, benefiting greatly from the compactness of silicon carbide electronics: "You're able to remove stuff and give passengers more legroom," Farnell said. The aircraft uses less energy for takeoff and cruising thanks to weight savings. Electric systems must withstand airplane vibrations and shocks from landings. High altitude adds insulation challenges due to dry air, and rapid switching can cause interference.
The flight verified that the engineering team met these aviation challenges. The UA Power Group emphasizes field testing beyond laboratory research. Mantooth said, "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."
Research Report:Development, Integration, and Flight Testing of a Silicon Carbide Propulsion Drive for a Hybrid Electric Aerospace Application
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