Joe Rodriguez wrote:

> To add my 2 cents worth.  You  guys with the high gross weights better be
> real careful with turbulent air penetration speeds  To the best of my
> knowledge, no one has recalculated this number for these high gross
weights.
> Ps.  I would really like to know how someone can get this much weight into
a
> IV and not be aft CG.  Scares me.


It seems that the CG issue is far more important.

Maneuvering speed, abbreviated Va, is called the rough air speed. It is
defined as the maximum speed at which full abrupt control deflection can be
made without exceeding the design load factor...Maneuvering speed is a value
of 1.9 Vs. It changes with a change in gross weight; decreasing as the
weight decreases (http://www.mountainflying.com/fly-low3.htm).

That is, as weight goes up, stall speed and maneuvering speed go up with it.
Therefore, you can penetrate turbulence at higher speed when heavy than when
light.

On the other hand, keeping the CG within proper bounds greatly affects
controllability. Forward CG may make controlled landing difficult or
impossible, while aft CG may make control impossible in any flight regime.

Ted Noel