Thing is, the scramjet is capable of 5000mph, but it doesn't mean you have to use it at 5000mph. If it was used at 2000mph, that would be fast enough for the time being. I would've thought the Gs at 5000mph would be significant? The concorde only failed because they weren't being maintained right. The concorde was grounded when one crashed into france. However... here's the trick, we had the technology to build one all those years ago, and technology has improved since then, why can't we just make new ones? An old car is more likely to break than the same car brand new, so it's the same for anything else. We could make a concorde with all the uncrashable technology from the Boeing planes, and a much stronger constructed body... I'd pay to go to america in a concorde. It's a case of, if the concorde was brought back I'd definately go, but as it is, it could be a long time.