This paper describes the XML based multidisciplinary tool integration in a conceptual aircraft design framework, developed by the Division of Fluid and Mechatronic Systems (FluMeS), Linköping University. Based on a parametric data definition in XML, this approach allows for a full 3D CAD integration. The one-database approach, also conducted by many research organizations, enables the flexible and efficient integration of the different multidisciplinary processes during the whole conceptual design phase. This central database approach with a detailed explanation of the developed geometry description and the data processing, focusing on the CAD integration is presented. Application examples of the framework are presented showing the data build up and data handling.