Pete:

Let me elaborate on my terse response (and see my response to Tony).
I agree that maneuvering speed, as defined in the aerodynamics books,
must be scaled with weight. However, Va, which is called DESIGN
maneuvering speed by the FAA, doesn't really match the definition of
plain ole "maneuvering speed". They really should have called it
something else, IMO.

However, it appears that most manufacturers are shooting for a
maneuvering speed, even though the regulations don't require it. If,
however, they chose to make the speed higher for some reason, it won't
protect you from overstressing the airplane, and neither will the
speed when you scale it for weight. GIGO. ;-)

Still, all this is of only academic interest. The one thing that IS
known is that the control surfaces must be protected at VA, and that
won't scale UP from published Va. Agreed?