Because you wish it.
On a more serious note, I suggest that you give it a shot. SB scale is more forgiving of detail inaccuracies than FD scale is, and I'd be happy to offer advice if you tried, but right now you've got 51 posts. All but something like 4 of them are you asking other people to draw large widebody aircraft in SB and FD scale for you.
Well, once I am able to install pc bootcamp on my mac computer, then I'll probably do it