4.1. .
index scales or tables for loaded items
4.1.1. Graphical balance chart
On the graphical balance chart the .index value for each item loaded . passenger or cargo . is
read on a diagram.
One scale per cargo compartment and one scale per passenger cabin section are represented.

The scales are made of oblique lines, with distance between 2 lines representing the .index
corresponding to the individual cargo weight or passenger number, usually presented on the
right end of each scale.
The oblique lines have been introduced in order to ease the manual drawing on the document.
Indeed the first possibility is to have vertical lines but is it difficult to determine the end point of
the drawing.

.Index

Pitch
Whereas with oblique line the horizontal and vertical lines can be more easily drawn.

Pitch To draw the pitch between two line use the .index(1 kg) value.
(H .
arm .
H)
item Ref
.Indexitem(1kg) =
 and determine the .index(XXX kg) or .index(XX PAX)
C needed on the balance chart.
Note 1 : the horizontal distance between the oblique line top and bottom points represents exactly .index(XXX kg) or .index(XX PAX) on the index scale.
Note 2 : the oblique line orientation : from top right to bottom left in case of forward CG movement, and from top left to bottom right in case of aft CG movement when loading the item must be strictly applied, because of the habits taken when manually using a balance chart. A change in the orientation may lead to misusing of the document.

C. BALANCE CHART DESIGN

Note 3 : the fuel loading .index used to be drawn on similar scales for some specific aircraft, nevertheless today due to the complexity of the refuel vectors and the high impact of fuel density on the fuel vector, this graphical method is no more used for Airbus aircraft.
4.1.2. Tabulated balance chart
a) Tables with constant step in index
Those tables are usually used for passengers and cargo .index for fuel .index tables with constant step in weight are used.

CARGO n

.index
203
+1
611
+2
1018
+3
1426
+4
1833
+5

CARGO n 
Weight (kg)  .index 
0 
+0
204 
+1 
612 
+2 
1019 
+3 
1427 
+4 

Building this type of table consists of determining the transition weights for which there is a step
between one index value and the other.
In the above example : 

. For weight between 0 and 203 kg the .index value varies between 0 and 0.49… . For weight between 204 and 611 kg the .index value varies between 0.5 and 1.49… . …
　
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本文鏈接地址：Getting to Grips with Aircraft Weight and Balance(85)