Aviation is chasing the next big leap in propulsion – one that leaves behind fossil fuels without sacrificing power, range, or safety. While electric flight was once considered a niche experiment, advances in battery technology, alternative fuels, and hybrid systems with hydrogen are quickly changing the picture. Startups and major aerospace manufacturers alike are exploring what the skies might look like in the next decade. The race is no longer about whether sustainable flight will happen, but how it will happen in the short term.
Hydrogen in aviation
Hydrogen has emerged as one of the leading contenders. Its energy density is far greater than lithium-ion batteries, and when used in fuel cells, it emits only water vapor. However, building reliable systems for aviation poses serious challenges – from storage to cooling to certification. That’s why a hybrid approach, combining electric propulsion with hydrogen fuel cells, is gaining traction among innovators seeking real-world application within this decade.
ZeroAvia, a U.S.-based startup focused on hydrogen-electric aviation, has positioned itself at the forefront of this hybrid movement. The company has already conducted successful test flights using “inflammable air” fuel cells and electric motors, aiming to develop propulsion systems for regional aircraft. But to move from prototypes to commercial reality, regulatory approval is key – and that process has just taken a major step forward.
ZeroAvia is creating a powerful electric propulsion system
The FAA and ZeroAvia have reached an important milestone, agreeing on a certification basis for the company’s 600-kilowatt electric propulsion system, which is a core part of its planned ZA600 hybrid powertrain. This was confirmed when the FAA issued ZeroAvia a G-1 issue paper outlining the criteria for certification.
ZeroAvia developed this electric propulsion system (EPS) specifically for the ZA600, but it’s also being offered to original equipment manufacturers (OEMs) as a standalone system. It could be used with a range of aircraft types and power sources, including battery-powered, hydrogen fuel cell, and hybrid models, for both airplanes and rotorcraft.
Val Miftakhov, ZeroAvia’s founder and CEO, pointed out that while hybrid technology is seen as the future for many commercial routes, improvements in electric propulsion and aircraft design are opening new opportunities for shorter-range electric flights. He said that certifying the 600kW propulsion system will help the company broaden its market and push toward cleaner aviation.
How does the hybrid system work?
The EPS itself is made up of four 200-kilowatt bidirectional inverters, which convert DC to AC power and supply electricity to a direct-drive motor capable of spinning at up to 2,200 rpm. The ZA600 powertrain pairs this electric system with hydrogen fuel cells, aiming to retrofit regional planes like the 19-seat Dornier 228 turboprop for more sustainable operations. ZeroAvia also plans to sell the EPS and other components separately from the full powertrain.
Production of these parts is underway at a facility opened last year in Everett, Washington. While the company’s headquarters are in Hollister, California, much of its research and development takes place in the UK. There, ZeroAvia is working with the UK Civil Aviation Authority to build “water-powered” refueling infrastructure and to certify its hybrid engines.
Another project – but coming to Seattle next
The company is also preparing a retrofit project at Paine Field near Seattle, where a de Havilland Dash 8-400 will be upgraded with the ZA2000 propulsion system, a more powerful setup designed for regional turboprops carrying 40 to 80 passengers. ZeroAvia expects to begin installing ZA600 conversion kits under supplemental type certificates later this year, with ZA2000 units to follow in 2027. With close to 3,000 orders for its powertrains and components, ZeroAvia sees certification as a major step toward making clean, efficient air travel a reality worldwide.