THE increasing complexity of advanced aerospace vehicles, together with the decreasing number of similar designs, has established the need for improved ways to utilize the capabilities of computers to support the total design process and to include more detail in preliminary design. A software system intended to meet this need is currently in the definition stage. This system is denoted Integrated Programs for Aerospace-Vehicle Design (IP AD) and a partial description of its over-all goals is given in Ref. 1. This paper describes results obtained from a small-scale experimental computer aided design system developed at the Langley Research Center as a part of the basic research supporting the IP AD development effort. This system takes into account a limited number of disciplines with a significant depth of detail in each, and represents only a small fragment of the total preliminary design process; however, the …