On May 31, 6:23*pm, Carl Baxter
wrote:
I'm trying to make sense of the weight and balance section in the
ASK-21 manual but having no success. *They give an equation for r sub
R, which I assume is the empty CG, but it's not specifically called
out. *The units don't balance; there is length on one side of the
equation and length squared on the other. *There is an example given
for calculating "inflight CG" and the results seem to be out of
limits *but they don't comment so I'm not sure I've got that right.
There is a Load Envelop with Empty Weight on the abscissa and r sub R
on the ordinate. *Where does the in flight CG come in? Or is r sub R
also the inflight CG

At 360kg (the nominal empty weight of the aircraft) there is only 8 mm
of CG range within the envelop. *Is it really that small? *I
understand the Schweizer weight and balance calculations but the
English translation of the Schleicher manual has me puzzled.

Any help would be appreciated. *Thanks.

Carl

r sub R is the calculated empty weight CG location relative to the
leading edge of the wing at the root.
It is also shown in the vertical axis of the diagram below.
The manual assumes most pilots will use the diagram, however the
information to calculate flight Cg is avaialable on the following
pages. Note that the only place(that I saw) where rear pilot moment
is shown is in the example calculation. Note that moment values of
pilot masses are negative.
Good luck
UH