3-D Interactive CADAM allows for easier construction, modification, analysis, and display of 3-D geometry surfaces and wire-frames. This research forms a basis for preliminary aircraft geometric design using the CADAM system. The helicopter design program, HESCOMP, originally a batch mode program, was coupled with CADAM via the CADAM data base such that the analysis, design, and redesign of the helicopter geometry and interior equipment geometry can be accomplished interactively. HESCAD, a program which produces the helicopter preliminary design model and enables the interior equipment design process, is developed. It provides a capability to evolve rapidly and refine helicopter configurations generated automatically using output from HESCOMP or interior equipment design by graphically and numerically defining helicopter components through interactive, on line, computer graphic display devices. Helicopter 3-D wireframes are automatically produced for any HESCOMP helicopter geometry output. A method which directs CADAM to analyze the helicopter components and produce weights, centers of gravity, moments and products of inertia and to review the results of the analyses directly on the screen is provided. This research was sponsored by IBM Corporation Federal Systems Division under contract No. 417503-DE. This thesis describes and illustrates the HESCAD program. Detailed graphical results are also presented. / Master of Science / incomplete_metadata