On Dec 16, 6:48*am, wrote:

OK oops- I have to admit not paying large amount of attention to
variable CG since I don't remember the last time I flew above about
480kg.

Glad to know we have the same limits. Even out West I have never
filled the glider. My typical ballast load puts me at 497kg. (9.7 psf
loading)

So back to the point that got me interested in this discussion:


Gives adequate pitch authority to pull to max lift coefficient, thus
tightest turn. From my experience, this is usually about 75-80% aft in
manufacturer's approved range.
UH

It's not quite that simple though is it?

The statement about optimum cg should perhaps be:

"Optimum cg is usually about 75-80% of the manufacturer's approved
range at minimum flight mass, but no further aft than the aft limit at
the actual flight mass."

BTW I manage my cg to be about 320mm dry and 305mm ballasted. I want
the cg to go aft for better climb performance if I dump because of
weak conditions. I have to change that at Parowan (strong conditions
and no ballast) so I add a nose trim disc to bring the dry cg to about
310 so I don't run out of trim in the fast glides. (For those that
want that in percent of limits the minimum flight mass range is
227-345mm).

Andy