W
EIGHT AND
B
ALANCE
R
EVISION
:
-
D
ATE
:
12/29/04
P
AGE
:
9
Copyright
2004 Glasair Aviation, LLC Arlington, Washington All rights reserved
5-3 FLIGHT CG CALCULATIONS
Calculate the flight CG of your Sportsman in “worst-case” loading
scenarios—extreme forward and extreme aft CG conditions—to see
where your Sportsman’s CG falls relative to the acceptable CG range.
The results of these calculations will establish guidelines for safely
loading your Sportsman for flight.
To perform the forward and rearward CG limit checks, tabulate the
weights, stations and moments, as shown in the following examples.
Add the weights and moments and divide the total moment by the total
weight to obtain the station of the CG. Once you have that figure, use
the following formula to calculate the CG as a percentage of MAC:
. . . in which the station of the wing leading edge is
89.4
, and
the MAC is
44.0"
.
The following examples are based on the empty weight and empty-
weight CG of the Sportsman taildragger prototype;
your numbers will
vary!
NOTE
For all weight and balance calculations, note that gasoline
weighs 6 pounds per gallon.
CG%MAC =
Station of the CG Station of the Wing Leading Edge
MAC
X 100
−