Yeah, that is probably how they would do it. I just don't think a multi-mach jetliner is gonna happen in our lifetime. Energy costs alone would be crazy if you could even carry enough. Cost to build and design such a plane would be enormous, and pretty exotic materials need to be used because of the heat generated by the air hitting the airplane at those speeds. I fly a lot and as much as I hate the coach busses of the sky's, I think that's all were gonna get.