If you want it to spin 24/7, you have to make the propeller separate from the rest of the plane in the model, and create an animation for it spinning once, if you are using milkshape; which i'm assuming you are, do this:
Ok, well if you check off cycle, it will do the animation non-stop. Never ever stop... Until you switch weapons maybe.
If you started off at a simple 30 frame animation, then put the start to '1' and end to '30'.
I just kinda don't understand what your talking about.
It should still apply for vehicles, even if that quote was for animating a weapon.