This Special Issue contains selected papers from works presented at the 11th EASN (European Aeronautics Science Network) International Conference on Innovation in Aviation & Space, which was held from the 1st until the 3rd of September 2021. About 420 remote participants contributed to a high-level scientific gathering providing some of the latest research results on the topic, as well as some of the latest relevant technological advancements. Nineteen interesting papers, which cover a wide range of topics including characterization, analysis and design, as well as numerical simulation, are contained in this Special Issue.