American Firms Up Support For ZeroAvia's Hydrogen-Electric Engines

American Airlines has reaffirmed its confidence in hydrogen as a way to help decarbonize aviation by signing a conditional purchase agreement with ZeroAvia for 100 hydrogen-electric engines to power regional jets.

The airline has also increased its investment in the U.S.-UK startup.

The announcement of the deal comes just days after rival hydrogen-electric propulsion startup Universal Hydrogen confirmed it was closing its doors after failing to raise additional funding. ZeroAvia says it is well capitalized, with strong support from investors.

Following up on a memorandum of understanding signed in August 2022, American has conditionally agreed to purchase ZeroAvia’s 5-megawatt-plus ZA2000RJ fuel cell engines, which are planned to be available in 2029 for retrofit to regional jets, including the Bombardier CRJ700s and CRJ900s operated by American.

“Advancing the transition of commercial aviation to a low-carbon future requires investments in promising technologies, including alternate forms of propulsion,” American CEO Robert Isom said in a statement. The airline first invested in ZeroAvia in 2022.

In June 2023, ZeroAvia and CRJ type certificate holder MHIRJ completed an initial technical study that identified an entry point for a CRJ700 retrofit with the ZA2000RJ, confirming maximum takeoff weight, center of gravity and structural allowances.

The study indicated that the hydrogen-electric CRJ700 could support up to 60 passengers with a range of up to 560 nm, covering more than 80% of current CRJ flights. The engines would have increased-diameter geared ducted fans or open rotors to overcome the loss of turbine core thrust.

ZeroAvia must complete several steps before it is ready to deliver the CRJ retrofit. First the startup must certify its initial product, the ZA600, a 500-750-kW hydrogen-electric engine designed for 9-19-passenger aircraft and on track for certification by the end of 2025, the company says.

Designed for Part 23 aircraft, the ZA600 uses pressurized gaseous hydrogen storage and low-temperature proton exchange membrane (LTPEM) fuel cells from Sweden’s PowerCell. A demonstrator engine has flown on a Dornier 228 testbed, and the first certified application is to be the Cessna Caravan.

Next, ZeroAvia must complete development of its high-temperature proton exchange membrane (HPTEM) fuel cell for the ZA2000—technology it brought in house when it acquired startup HyPoint in 2022. HTPEM offers higher power density than LTPEM with lower system complexity and weight.

With the ability to operate at up to 200C (390F) compared with 80C for LTPEM, simplifying thermal management, HTPEM has the potential to exceed a system-level power density of 3 kW/kg, says ZeroAvia, which has demonstrated 2.5 kW/kg. The study with MHIRJ assumed 2.4 kW/kg.

HTPEM fuel cell stacks are planned to fly for the first time in 2024 in a coaxial-rotor helicopter demonstrator being built by Piasecki Aircraft. And, with support from Alaska Airlines, ZeroAvia is modifying a De Havilland Canada Dash 8-400 into a flying testbed for the higher-power ZA2000 engine.

Aimed at Part 25 aircraft with 30-90 seats, the ZA2000 series will use liquid hydrogen storage to provide longer ranges up to 1,000 nm. ZeroAvia has also brought its electric motors in-house and is developing a 900-kW motor, stackable to produce up to 5.4 megawatts, for the ZA2000 family.

Its incremental approach to the market and in-house development of technology differentiates ZeroAvia from Universal Hydrogen, which was focused on bringing a fuel cell-powered ATR 72 retrofit to the regional airline market to pump-prime demand for its planned hydrogen fuel-supply services.

“In signing this purchase agreement and furthering its investment, American is supporting our mission of innovation for clean aircraft propulsion and it is a good signal that ZeroAvia is delivering on our technology roadmap,” ZeroAvia Founder and CEO Val Miftakhov said in a statement.