Research initiatives in hybrid-electric/sustainable aviation typically address only a single vehicle or single vehicle class. However, it can be expected that for novel propulsion and energy solutions to reach a sufficient maturity level an approach not too different from the early days of aviation could be followed: starting small to prove a technology and gradually scaling it up to larger and larger classes of vehicles. Therefore, it is important to sketch a landscape of technologies and identify areas suitable for scaling, as well as limitations or challenges for development. The CHYLA project aims to contribute to the overall research and development in sustainable aviation by providing exactly this; an overview of scaling opportunities, challenges and limitations of key radical technologies where the credibility of underlying technology assumptions is an explicit factor in developing such a landscape. In CHYLA we introduce the concept of “credible aircraft design”, which refers to the influence of the uncertainty in the assumptions behind the design to quantify how realisable, or in other words, how credible, is the design. Since technical work on the project has just started, the article will present a general overview of the CHYLA scope, approach and objectives.@en