The Out of the Box initiative was funded by the European Commission DG-RTD in the frame of the Advisory Council for Aeronautic Research in Europe (ACARE). The initiative aimed at identifying innovative, discontinuous, revolutionary and radical concepts and technologies for air transport of the future. The Out of the Box project had two phases. In phase one, creative ideas and concepts were identified. In phase 2, these ideas were assessed based on their feasibility in terms of customer acceptance, economics, efficiency and technologies. A limited number of ideas were identified as having the... best potential to achieve radical changes. The topics include novel sustainable propulsion concepts and the use of ground power to increase the efficiency of flying, autonomous guidance and control for air vehicles, personal air transport systems, novel ways to connect people with aircraft and the concept of the airborne cruiser and its feeder aircraft. The Out of the Box initiative enables a more structured approach for thinking about radical changes in Air Transport on a European level. It also provides a mechanism for other transport modes to gather ideas about the longer term future and to promote radical changes in those sectors.