We all know that the Brits were a flop when it came to producing and marketing airliners in the past.
... I don't know, they sold the HS125 to Raytheon quite effectively
Interesting snippet from this weeks "Professional Engineering". NASA has apparently funded two SST engine studies by Rolls Royce, who reckon that their engineering database on engines for SST is worth about US$2bn, that being their estimate of how much it would cost to repeat all the work and learn the same lessons.
The two studies have been of a high-bypass supersonic engine, and a smaller mixed geometry engine - respectively in co-operation with Gulfstream and Lockheed Martin.
The next stage may apparently be a DARPA funded demonstrator, particularly to allow them to develop ways of minimising environmental effects.
G