Actually a pretty smart design; raptors' spread primaries provide considerable extra lift. It probably can't be built as depicted without some pretty impressive

Actually a pretty smart design; raptors' spread primaries provide considerable extra lift. It probably can't be built as depicted without some pretty impressive materials science work and maybe a novel discovery or two, but that's okay; it isn't intended to be built as depicted in the first place. I'll be interested to see if anything comes out of it over the next couple of decades.