Flyout is ot in development yet but it’s some sort of sandbox creation for aircraft with a serious dose of simming generously applied on top.
The interesting thing this youtuber does is asking GPT to define the characteristics of a stealth fighter and tried to see if that would work or not.
More info about the game are found here:
A more classic example of plane-building
That looks like a lot of fun!
Was it FS4 that had an airplane editor? A lot simpler than that, of course, but I spent many hours making my own planes. I also made a few fpr X-Plane 5 or was it 6?
Definitely is was a FS, I can’t recall which.
I think this game has potential- as in the developers are having a really clean direction.
Time will tell. 
I can see this being a lot of fun. Imagine some of the designs this forum could come up with 
Only viable design is the 
I remember that too! Spent many hours (painfully) designing the most awesome supersonic fighter jets, only to be unable to get them to actually fly right. 
Looks very cool! A bit like ‘SimplePlanes’, but without the Simple part 