Originally Posted by
Gadget freak
The velocity vector or flight path marker symbology in many aircraft shows climb/descent angle.
(a) I'm not sure I'd trust that for flight mechanics research.
(b) I'm guessing that's based on GPS, which is definitely NBG for flight mechanics work, which you want to be based upon an understanding of what's going on in the parcel of air you're flying in at the time - not earth axes.
G