Aviation maintenance, repair and overhaul (MRO) is essential for ensuring airworthiness and aircraft safety. With its inherent focus on repair and life extension, it is also a natural contributor to the principles of the circular economy (CE). However, the potential of MRO to foster a sustainable aviation sector remains largely unexplored. This thesis investigates how the MRO sector, in the context of the Royal Netherlands Aerospace Centre (NLR), can develop the necessary knowledge and capabilities to incorporate circular economy principles into its operations. Through a comprehensive literature review, company positioning analysis, qualitative empirical research and a design phase, the
study identifies the key enablers and barriers to circular innovation in the aviation MRO sector. The findings reveal a fragmented understanding of sustainability, as well as structural and cultural obstacles to cooperation and critical knowledge gaps. To address these issues, the thesis proposes a phased knowledge development roadmap, as well as a practical learning tool. These include a CE knowledge development roadmap and storybook. These outcomes aim to support NLR in developing a shared language and paving the way for it to become a circular specialist.