Quote Originally Posted by Biscuit View Post
One of the biggest hurdles with supersonic passenger planes is the sound. I don't know if you have ever heard the sonic boom but they can genuinely be heard across entire counties. This means you need a plane that's capable of flying both sub (for above residential areas) and supersonic for reasonably long distances.

If they could develop an upgrade path that fits within the existing limitations of the transport systems, I think more people would step up and take notice.
That was one of the problems with Concorde - the only place it could go supersonic was over large Oceans - like the Atlantic and Pacific. So flying to the Middle East supersonically was trick as supersonic flight wasn't possible until it reached desert regions.

The other problem was the limited passenger load - wide bodied subsonic jets were far more fuel efficient in terms of fuel/passenger mile.