The scenario analysis aims to support strategic efforts to end aviation’s dependence on fossil fuels by creating reasonable, consistent pictures of what the future might look like. We focus on the external environment indeveloping the scenarios. This involves taking a look at potential developments leading up to 2045 of the factors which have major relevance for fossil-fuel-free aviation but are beyond the control of ecosystem actors and stakeholders.The scenario narratives we have produced contain descriptions of the business sector, politics, society, and technology and infrastructure, and capturethe developments of the following factors: global travel and consumer pressure for sustainable travel, raw material competition, the oil industry, the willingness to make sustainable investments, electrification and decentralisation, and disruptive technologies and business models.