American Airlines today announced that it has entered into a conditional purchase agreement with clean aviation innovator ZeroAvia for 100 hydrogen-electric engines intended to power regional jet aircraft with zero inflight emissions save for water vapor.

In addition, American has increased its investment in ZeroAvia. American made its first investment in ZeroAvia in 2022 and has also now participated in the company’s Series C financing round. The engine agreement follows the Memorandum of Understanding the companies announced in 2022.

ZeroAvia is developing hydrogen-electric (fuel cell-powered) engines for commercial aircraft, which offer the potential for close to zero inflight emissions. The company is flight testing a prototype for a 20-seat plane and designing an engine for larger aircraft such as the Bombardier CRJ700, which American operates on certain regional routes.

“Advancing the transition of commercial aviation to a low-carbon future requires investments in promising technologies, including alternate forms of propulsion,” said American’s CEO Robert Isom. “This announcement will help accelerate the development of technologies needed to power our industry and uphold our commitment to make American a sustainable airline so we can continue to deliver for customers for decades to come.”

The investment and conditional commitment to purchase novel engine technology contributes to American’s aggressive goal to achieve net-zero greenhouse gas emissions by 2050. In recent years, American has undertaken the most extensive fleet renewal effort in the history of commercial aviation, which currently gives it the youngest mainline fleet of any major U.S. network carrier and improves fuel efficiency. American has made industry-leading investments in sustainability, including finalizing an offtake agreement with Infinium, a producer of next-generation low-carbon sustainable aviation fuel, and becoming the first customer of Graphyte’s innovative and permanent carbon removal process.

“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,” said ZeroAvia Founder and CEO Val Miftakhov. “The solutions that can serve the largest airlines are within reach, and the clean future of flight is coming.”

ZeroAvia’s hydrogen-electric engines use hydrogen in fuel cells to generate electricity, which is then used to power electric motors to turn the aircraft’s propellers. The only inflight emission is low-temperature water vapor, and the lower intensity electrical systems have the potential to offer significant cost savings.