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…
. … Note : The same examples apply for passenger .index table except that the weight is replaced by the number of passengers.
In those tables the user selects the .index corresponding to the weight or passenger number
range he is considering.
For each weight range the .index range is 1 index value.
So selecting the rounded figure the user generates an maximum inaccuracy of ±0.5 index unit in
each table.
The inaccuracy due to one table is independent from the inaccuracies due to the other tables so :
WEIGHT AND
BALANCE
ENGINEERING
222 2 2
E =±
E cargo1index table + E cargo2 index table + E cargo3 index table + E cargo4 index table + E cargo5 index table
cargo index tables
222Epassenger index tables =±
E cabin OA index table + E cabin OB index table + E cabin OC index table + K
WEIGHT AND
BALANCE
C. BALANCE CHART DESIGN
b) Tables with constant step in index
Those tables are usually used for fuel .index or for all .index tables in the balance chart.
WEIGHT (kg) DENSITY (kg/l)
0.785
3000 4000 5000 6000 7000 8000 +2 +1 +0 .2 .4 .7
In those tables the user selects the .index corresponding to the weight or passenger number he
is considering. For a weight value not presented in the table different solutions are available : . interpolation allowed : the user finds the .index by interpolating between the 2 closest .index values. Ex: for weight of 6500 kg the .index is .3. In this case the maximum inaccuracy value is reached for the maximum range of .index between two weights and the inaccuracy value equals half the .index range. Ex: in the above table the maximum .index range is between 7000 kg and 8000 kg and corresponds to a maximum inaccuracy in index of ±1.5 index units.
. interpolation is not recommended by the operator procedure, the user always retains the value corresponding to the lowest (highest) weight. Ex: for weight of 6500 kg the .index is .2 (.4). In this case the maximum inaccuracy value is reached for the maximum range of .index between two weights and the inaccuracy value equals the .index range. Ex: in the above table the maximum .index range is between 7000 kg and 8000 kg and corresponds to a maximum inaccuracy in index of ±3 index units.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：Getting to Grips with Aircraft Weight and Balance(76)
