The process of conceptual aircraft design has advanced tremendously in the past few decades due to rapidly developing computer technology. Today’s modern aerospace systems exhibit strong, interdisciplinary coupling and require a multidisciplinary, collaborative approach. Efficient transfer, sharing, and manipulation of aircraft design and analysis data in such a collaborative environment demands a formal structured representation of data. XML, a W3C recommendation,is one such standard concomitant with a number of powerful capabilities that alleviate interoperability issues in a collaborative environment. A compact, generic, and comprehensive XML schema for an aircraft design markup language (ADML) is proposed here to represent aircraft conceptual design and analysis data. The purpose of this unified data format is to provide a common language for data communication, and to improve efficiency and productivity within a multidisciplinary, collaborative aricraft design environment. An important feature of the proposed schema is the very expressive and efficient low level schemata (raw data, mathematical objects, and basic geometry). As a proof of concept the schema is used to encode an entire Convair B58. As the complexity of models and number of disciplines increases, the reduction in effort to exchange data models and analysis results in ADML also increases.