The international economic stakes are high. In December 1995, a single aircraft concept was chosen to focus the intensive technological development planned for the next three years of the HSR program. The TCA evolved from separate Boeing and McDonnell Douglas HSCT designs. Computer modeling and wind tunnel tests were used to produce a single concept with superior aerodynamic performance and operational characteristics, which also satisfied environmental goals. The technology focus also was significantly narrowed in the areas of propulsion and airframe structural components.
Technical challenges remain in each area, however, though significant progress has been made.
Structures and Materials New high-temperature materials and structural concepts were selected for fabrication and testing of various subcomponents in the TCA's fuselage and wings. Selecting the right structures and materials for an airframe designed to fly 60,000 hours in its lifetime, in temperatures approaching 350 degrees Fahrenheit, is critical to making a future supersonic transport economically feasible. Weight and manufacturing costs must be minimized, while strength and durability are maintained. After much design, analysis and testing, the many different structural concepts studied early in the program were narrowed down to two types. This allows the program to focus on the lightest weight, highest performance designs and move from testing small coupons and elements to testing large panels.