American Airlines has invested in zero-emission propulsion developer ZeroAvia and signed a memorandum of understanding covering a possible order for 100 hydrogen-electric engines to retrofit CRJ regional jets.

The amount of the investment has not been disclosed. American is the latest carrier to invest in the U.S./UK startup, which is developing hydrogen fuel-cell powertrains for retrofit to regional turboprops and jets spanning 9-80 passengers. 

United Airlines invested in ZeroAvia in December 2021 with a similar deal that includes the potential to purchase up to 100 powertrains for retrofit to 50-seat CRJ-550s operated by United Express.

Alaska Airlines participated in the same $35 million fund-raising round at the end of 2021. That deal includes collaboration on development of a hydrogen-electric powertrain for the 76-seat De Havilland Canada Dash 8-400 regional turboprop. International Airlines Group is also an investor in ZeroAvia.

American’s investment comes as Congress prepares to vote on the U.S. Inflation Reduction Act, which includes support for hydrogen production through a new tax credit of up to $3/kg for low-carbon hydrogen, subject to meeting carbon intensity and other requirements.

“We are heartened by the Inflation Reduction Act’s proposed investments in reduced emissions and a clean energy future, particularly measures in support of hydrogen production,” ZeroAvia told Aviation Week. “The Act will be an important accelerant in our pursuit of zero-emission aviation powered by hydrogen fuel-cells, and it shows that the U.S. is once again prepared to be a leader in the global fight against climate change.”

The ZA2000-RJ powertrain for retrofit to the CRJ will be a version of the 2-5-megawatt ZA2000 liquid-hydrogen powertrain family now under development. The ZA2000 is a follow-on to the 600-kW ZA600 gaseous-hydrogen powertrain that will shortly enter flight testing at ZeroAvia’s UK base. 

The ZA600 will be flown on Do 228 propulsion testbeds at Kemble, England, and Hollister, California. ZeroAvia is aiming for certification and market entry in 2024. The launch aircraft has not been announced, but in addition to the Do 228 candidates include the Cessna Caravan and De Havilland Twin Otter.

The ZA2000-RJ powertrain is planned to be available by the late 2020s. “Our investment in ZeroAvia’s emerging hydrogen-electric engine technology has the potential to play a key role in the future of sustainable aviation,” American Airlines CFO Derek Kerr said in a statement.

ZeroAvia is working with Mitsubishi Heavy Industries’ MHI RJ Aviation unit in Montreal to certify the CRJ conversion. MHIRJ acquired the CRJ program from Bombardier in 2020 and supports the global fleet of aircraft.