thank you for your very interesting input. I think the full size aircrafts use gyroscopic effects
a lot. This type of tumble you have just described me a lot of people would mistakenly call
Lomcovak. I'm not really sure if I'm correct but the name "waterfall" they only use in 3D world.
Basicaly the plane is falling down somersaulting forward. In your description the plane tumbles
shoulder to shoulder and at the end it might end up going over the nose (if you get lucky)
In waterfall it seems to be controlled flipping over the nose over and over.
I might be wrong but that's just what I've observed.