Aircraft manufacturers and industry are working to bring climate-friendly hydrogen technologies to aircraft and build the necessary aviation infrastructure. Hydrogen has the potential to revolutionize aviation: Converted via fuel cell into electricity for electric motors, the energy-rich element paves the way to virtually emission-free flying. Modified aircraft gas turbines powered directly by hydrogen also no longer emit carbon dioxide. The nitrogen oxide emissions remaining with such CO2-free hydrogen combustion can be technically reduced to a minimum. But what do the concrete solutions look like? What plans does the industry have? And when will H2 reach the mass market? We talk about this with Prof. Dr. Josef Kallo, CEO of H2Fly.