Green hydrogen opens up great opportunities for the reduction of emissions, which is why it is being considered as a sustainable energy carrier by various sectors of the economy. Due to its physical properties being very different from today's kerosene fuel, however, hydrogen requires profound changes along the entire process chain from production to its use on the aircraft. Both, in aircraft and propulsion systems, it provides completely new technological options, but also many challenges that need to be mastered – both at the conceptual level and in detail. Equally affected are the infrastructure and supply processes on the ground. In order to make sound assessments of its suitability as an aviation fuel, a broad understanding of the role of hydrogen in the overall energy transition is crucial. Thanks to our interdisciplinary team at Bauhaus Luftfahrt, we are in an excellent position to address the essential questions around hydrogen aviation in a holistic manner.