In the prototypes when they folded back the wings the wings would start to melt from the heat of the engines.
The original SST was just a big waste of money. What killed the project is congress denied Boeing money to build it. Super sonic planes are for the military. Just look at the concord; they only built a handfull of the planes, and they could hardly turn a profit without government funding.
You're getting in the deep end of the pool there Catturd. I've known one of the engineers on the project for over 40 years.
Where did I claim an opinion that an economic supersonic transport could be built? Certainly, jet engine technology has advanced a great deal in 40 years, but supersonic flight remains very expensive. And the environmental issues are still there with NOx pollution of the stratosphere.