Japan Airlines (JAL) has partnered with hydrogen-electric propulsion startups H2Fly, Universal Hydrogen and ZeroAvia to explore the retrofit of its regional aircraft fleet with zero-emission powertrains.

JAL and its maintenance arm JAL Engineering Co. (JALEC) have signed memorandums of understanding (MOU) with the three companies to evaluate the powertrain requirements for various aircraft sizes and ranges.

Stuttgart, Germany-based H2Fly conducted the first flight of a fuel-cell-powered aircraft using liquid hydrogen in September using its HY4 testbed aircraft. The company is working with Deutsche Aircraft to convert the 40-seat D328 regional turboprop to hydrogen-electric propulsion for flight in 2025.

Universal Hydrogen (UH2) is flying a De Havilland Canada Dash 8-300 testbed with one of its two turboprops replaced by a megawatt-class hydrogen-electric powertrain. The U.S. startup plans to certify a conversion for the ATR 72 regional turboprop, aiming for entry into commercial service in 2026.

UH2 is also developing a hydrogen-supply system using modular canisters that are loaded into the aircraft. In March, the company launched a joint study with JAL of green hydrogen supply and logistics in Japan. This involves identifying local partners for hydrogen production, module filling and delivery.

The new MOU further involves JAL and JALEC in providing input on the technical design and development of the conversion kits, and the overall hydrogen value chain in Japan. “JAL will be able to promote the specifics of their regional operation with a strong focus on reliability and maintainability,” UH2 says.

ZeroAvia has flown a 19-seat Dornier 228 testbed with a fuel-cell powertrain replacing one of its two turboprops. The U.S.-UK startup is now developing the 2-5-megawatt-class ZA2000 powertrain to retrofit 40-90-seat regional turboprops, with service entry planned for 2027.

JAL and ZeroAvia “will collaborate on assessing operational parameters for retrofit hydrogen-electric aircraft for existing and prospective routes, as well as collaborating to define pathways for regulation, retrofit operations, hydrogen fuel infrastructure and engine maintenance, repair and overhaul,” ZeroAvia says.