A growing number of aviation stakeholders have recently shared their zero-emission visions, goals and roadmaps to shape a carbon-free aviation future and tackle climate change. These roadmaps often rely on developing breakthrough aircraft technologies powered with clean energies. One of the main innovative means proposed is a hydrogen-powered aircraft. Like for other disruptive concepts, hydrogen aircraft come with new challenges: from the design of the aircraft technology to its operation within the global network and the fuel there are being powered by. Beyond the engineering of the aircraft itself, it is imperative to ensure both the availability and sustainability of the hydrogen used to power these aircraft. This is a major challenge to overcome, given the current levels of green hydrogen production around the world and the growing interest in it from the entire transport sector.