The next generation SST is recognized that environmental and economical issues must be satisfied concurrently. In this paper, what are required, what and how should be done to satisfy these issues are discussed. Especially, emphasis is put on economical viability of the SST.
Key technologies for the SST realization are on drag reduction, composite material structure, quiet and low NOx emission variable cycle engine, low cost development and high maitainability aircraft design.
As a result of technology feasibility study, it is found that drag reduction technology is very important and especially, low speed aerodynamics is essential for environmental and economical issues. Required technology improvement to realize the SST is more than 20% for aerodynamic efficiency.