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COMPETITIVE ASSESSMENT OF TECHNOLOGY 107 Figure 5-1 Benefits Possible From Technology Improvements Source: Derived from NASA Technology Program for Future Civil Air Transp orts; H.T. Wright, Aerospace Industries Association of America, International Air Transportation Conference, June 1983, Montreal, Canada. Status of Technology Design Techniques The capabilities of modern high-speed computers have made possible the use of very sophisticated techniques for computational analysis in both aerodynamics and structures. Recent advances in computational aerodynamics have allowed transonic drag rise characteristics to be determined with a high degree of accuracy, thus allowing designers to develop airfoil shapes quickly to meet a variety of requirements. Computational aerodynamics techniques are also being applied to nacelle cowl design, afterbody design, and nacelle placement relative to the wing. The effect of these techniques is to reduce dependence on empiricism and experiment and to use fewer, but more representative wind tunnel tests for validation. The technology is also applicable to design processes for rotorcraft and general aviation craft. United States manufacturers are making extensive use of these techniques in design studies of the next-generation 150-seat
COMPETITIVE ASSESSMENT OF TECHNOLOGY 108 aircraft. Airbus Industrie is exploiting ongoing European research programs in computer-aided airflow modeling of the A320 wing. The goal is further reduction of drag while maximizing aerodynamic and structural efficiency. In structural analysis, the United States retains a lead in the ability to optimize designs through use of modern mathematical models in conjunction with modern large-capacity computers. In basic advanced wing design the status of the United States appears to be comparable with others. However, in transonic wing design, the United States is believed by the panel to have a slight lead over Europe and probably a larger lead over Japan due to pioneering supercritical wing work by NASA, which has been extended by U.S. airframe manufacturers and NASA. Computer-aided design and computer-aided manufacturing (CAD/CAM) are key new design techniques brought about by the revolution in interactive software developed for modern high-speed computers. CAD systems provide the capability for analyzing many different designs quickly and accurately. System optimization of complex interactive elements can now be easily accomplished, thus minimizing design lead time and cost. CAM systems allow selected designs to flow directly to the manufacturing process by providing computer-developed instructions for numerically controlled machines. About one-third of the Boeing 767 components were designed with the help of a computer, and about 5 percent of the B-767 design went straight from computer-aided design into numerically controlled machining. The resulting reduction in drawing errors is a major benefit as work is released onto the production line. Pioneered in this country, CAD/CAM technology has been quickly adopted abroad and is now standard practice at Airbus Industrie and in Japan. With the Messerschmitt (MBB) computer-aided design techniques, which are widely used for lofting and autodrafting, peaks and troughs of new design tasks can be handled without attendant manpower fluctuations. Ease of access by foreigners to CAD/CAM hardware and software developed in the United States assures that the European and Japanese aerospace industries can stay competitive in this technology in the future. The panel believes that not enough attention is being paid to the application of those powerful CAD/CAM tools to smaller aircraft. Thus, the U.S.- manufactured aircraft for small feeder lines and for limited markets, such as executive aircraft, may not be realizing their full technological potential and obtaining as strong a market position as possible.
