Chu Chu;
It seems to me that if Concorde "failed," it's only because it did not usher in an era of supersonic flight.
I would like to ponder the words, "usher in". . .
"Success" arrives, and sustains itself in many, many forms as does the more practical notion, "copied and improved upon" have many, many expressions.
Our age is one in which the yardsticks that popularly measure and make account of human endeavour are today exclusively material, and less broadly-speaking, financial.
That something must be a "commercial" success for it not to be a "failure" is a "local", temporal measure of our times.
By such "local" measures the U.S. Space Shuttle was a failure as was the Apollo program.
Yet we have Burt Ratan, Elon Musk.
Concorde was different than the "notion" of the "DC3", the "B707", etc. It seems to me that the success of Concorde is measured in knowledge and spirit, a demonstration of technical success and always a singular mark in our history of aviation. I know that the skill, imagination and "slugging in the trenches" over millions of difficult decisions on Concorde has materially contributed to aviation and specifically certain airplanes. The notion of "variations on a theme" is not the only measure of success!