In this report the practical feasibility of using hydrogen for civil aviation is evaluated by the compilation of a number of transition scenarios, which imply changing from a conventional fleet of aircraft to a LH2-fuelled fleet, over a certain time period. In order to accomplish this, SAS´s share of the Swedish domestic air traffic is investigated. Realistic transition scenarios are compiled, and the emissions related to these scenarios are estimated, and presented in relation to emissions of the conventional fleet. The fuel sources and infrastructure changes needed at the airport, and for distribution of the LH2 are identified and assessed. It may be concluded that an essential increase in airport capacity, at all airports, is required to cope with the increasing traffic demand. In all scenarios it is reasonable to change to a fleet powered with liquid hydrogen, solely, by 2050. The overall airport layout and procedures should not change, and the aircraft can be refuelled at gate positions exactly like conventionally fuelled aircraft. Largely, the required changes have to do with refuelling procedures. To make sure that no or very little fossil-based energy sources are used for the LH2 production, development and extension of renewable energy sources parallel to the introduction of cryoplanes is essential.