This document reflects the results of a fact-based study prepared by McKinsey & Company for the Clean Sky 2 JU and Fuel Cells and Hydrogen 2 JU (hereafter the Joint Undertakings). This study was jointly procured by the Clean Sky 2 JU and FCH 2 JU and received financial support under the H2020 Framework Programme. The following 24 companies and organizations provided inputs and contributed to this study: Airbus, Air Liquide, ArianeGroup, Ballard Unmanned Systems, Bauhaus Luftfahrt e.V., Boeing, BP International Limited, Cranfield University, Equinor ASA, easyJet Airline Company Ltd, German Aerospace Center (DLR), GKN Aerospace Services Limited, Groupe ADP, Hydrogenics (now part of Cummins Inc.), Intelligent Energy, Liege Airport, Linde Technology, Plug Power, PowerCell Sweden AB, Safran Group, Schiphol Group, Shell International Petroleum Company, TU Delft, and ZeroAvia.