United Airlines RJ-550 outfitted with ZA 6000 Engines

MIAMI – Today, United Airlines (UA) has become the largest airline to invest in zero-emission aircraft engines for regional aircraft.

In a press release today, the airline said it has taken an equity stake in ZeroAvia, a leading company focused on hydrogen-electric aviation solutions. Today’s news did not reveal the size of the stake.

UA expects to buy up to 100 of the company’s new zero-emission, 100% hydrogen-electric engines (ZA2000-RJ). This engine could be retrofitted to existing United Express aircraft as early as 2028. One potential use is on United’s unique CRJ-550.

Photo: Yifei Yu

United’s Statement


“Hydrogen-electric engines are one of the most promising paths to zero-emission air travel for smaller aircraft. This investment will keep United out in front on this important emerging technology,” said Scott Kirby, CEO of United. “United continues to look for opportunities to not only advance our own sustainability initiatives but also identify and help technologies and solutions that the entire industry can adopt.”

Per the release, hydrogen-electric engines use electricity created by a chemical reaction in a fuel cell to power an electric motor instead of burning fossil fuel. As no fuel is burned, there are no climate-harming emissions or carbon released into the atmosphere.

It is likely that the airline will use the ZA2000-RJ as a new power source for existing regional aircraft. Under the agreement with United Airlines Ventures, United will pursue a conditional purchase agreement for 50 ZeroAvia ZA2000-RJ engines. Also, there is an option for 50 more, enough for up to 50 twin-engine aircraft. United Express would operate those planes upon approval by regulators. That certification could come as early as 2028.

“This support by United, alongside our other forward-thinking partners, demonstrates the importance of hydrogen-electric propulsion in the future of sustainable flight,” said Val Miftakhov, founder and CEO and of ZeroAvia. “The United Express routes powered by hydrogen-electric aircraft will enable large numbers of passengers to take zero-emission flights well within this decade.”

According to the news from United, ZeroAvia is accelerating development of its ZA2000 engine. It will soon begin ground tests of its ZA600 in a 19-seat aircraft. The company aims to enter commercial service with this smaller engine by 2024.

United CRJ-550. Photo: Brad Tisdel

More Than Engines


Earlier this month, United operated the first passenger flight using 100% sustainable aviation fuel, from Chicago to Washington, D.C. The flight showcased the safety of sustainable aviation fuel and the potential for a dramatically reduced carbon footprint for aviation.

Also, earlier in 2021, United announced a record-setting agreement to purchase sustainable aviation fuel from Alder Fuels. The company has now committed to purchase more than twice as much of this fuel as all other airlines combined.


Featured Photo: United Airlines