I think we can infer that the plane is doing a similar manouver to this as from 30 seconds in
i.e. flying a helical path with the top of the plane pointing towards the centreline of the helix
That coaster (called the corkscrew) had over the shoulder restraints but they weren't needed to stop people falling out of the cars. you felt positive g i.e. your butt was being pressed into the seat to some extent at all times - the shoulder restraints were just there to stop idiots standing up.