ZeroAvia flew the world’s largest hydrogen-electric aircraft today in a step forward for sustainable aviation. The 19-seat, twin-engine Dornier 228 plane, fitted with a prototype hydrogen-electric powertrain, completed a 10-minute flight from Cotswold Airport in the UK. It was part of the HyFlyer II project, a government-funded R&D program working to make small passenger planes better for the environment.

The powertrain was fueled using “compressed gaseous hydrogen produced with an on-site electrolyzer.” The testing configuration included two fuel-cell stacks and lithium-ion battery packs housed in the cabin for the test. However, for commercial use, they would move to external storage to make room for seating. In addition, it was paired with a Honeywell TPE-331 stock engine on the right wing for extra power during takeoff and safety-related redundancy.

Here’s ZeroAvia’s promotional footage of the flight (including some delightfully over-the-top music):

ZeroAvia says it’s on track to certify the technology this year, with plans for commercial routes by 2025. The company is also working on a 2-5 MW powertrain program that will scale the technology for aircraft up to 90 seats; the goal is to expand into narrow-body planes in the next decade. In addition, Amazon has invested in the company as part of its Climate Pledge Fund.