"The conceptual design is the early stage of aircraft design process where results are needed fast, both analytically and visually so that the design can be analyzed and eventually improved in the initial phases. Although there is no necessity for a CAD model from the very beginning of the design process, it can be an added advantage to have the model to get the impression and appearance. Furthermore, this means that a seamless transition into preliminary design is achieved since the CAD model can guardedly be made more detailed. For this purpose, knowledge-based aircraft conceptual design applications Tango (Matlab) and RAPID (CATIA) are being developed at Linköping University. Based on a parametric data definition in XML, this approach allows for a full 3D CAD integration. The one-database approach, also explored by many research organizations, enables the flexible and efficient integration of the different multidisciplinary processes during the whole conceptual design phase. This paper describes the knowledge-based design automated methodology of RAPID, data processing between RAPID and Tango and its application in the courses ‘‘Aircraft conceptual design’’ and ‘‘Aircraft project course’’ at Linköping University. A multifaceted user interface is developed to assist the whole design process."