How fast can an H₂ aircraft be refueled? How can fuel cell stacks be checked for defects during operation? And what technologies are needed for a multi-megawatt propulsion system? These questions were at the center of the ZAL Diskurs on February 20, 2025.

The focus was on the HEROPS project (Hydrogen-Electric Zero Emission Propulsion System), which is developing technologies for a climate-neutral, hydrogen-powered electric propulsion system—aiming to bring regional aircraft into the air by 2035. Dr. Stephan Lellek (MTU Aero Engines) compared alternative energy sources and propulsion systems, concluding that only hydrogen-electric is both emission-free and scalable.

A solution for storing liquid hydrogen was presented by Dr.-Ing. Marko Vietze (MT Aerospace AG). While comparable systems often rely on cryopumps, his team developed a **passive system with heat exchangers**, regulating gas pressure without moving parts—a key advantage for maintenance and reliability.

Hydrogen will also fundamentally change aircraft maintenance. Dr. Lothar Kerschkens (Lufthansa Technik) outlined the new **MRO challenges** facing the industry: high-voltage systems that cannot be touched and the question of how **fuel cell stacks can be efficiently inspected** within short turnaround times.

The extensive Q&A sessions after each presentation made one thing clear: there is great interest in emission-free aviation—as well as many open questions about infrastructure, technology, and hydrogen supply.

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