Computations Using Weight and Moment Indexes
If the weight and balance data uses moment indexes
rather than arms and moments, this same alteration can be
computed using a chart like the one shown on Figure 5-4.
Subtract the weight and moment indexes of all the
removed equipment from the empty weight and moment
index of the airplane. Add the weight and moment indexes
of all equipment installed and determine the total weight
and the total moment index. To determine the position of
the new CG in inches aft of the datum, multiply the total
moment index by 100 to get the moment, and divide this
by the total weight to get the new CG.