One of the core bottlenecks with respect to the continued growth of aviation in the coming 40 years is the airport itself. The 2050+ Airport project investigates the step change innovation needed for the airport to enter the second half of this century. Three concepts are being researched: a time-efficient, cost-effective and ultra-green airport. To support the development of future concepts, the Concept Development Methodology is created. It builds upon the Value Operations Methodology to develop each airport concept and assess the expected benefits for the different users in 2050. The main contribution of this paper is to highlight the development of the Concept Development Methodology and to outline its individual steps. It is shown that the methodology is fit for application in the draft development stage, but further work is required to support detailed concept evaluation. Particularly the Change-Impact sub-method is promising and as such requires more research.