. ex : A320-200 Takeoff forward operational limits determination 
Weight W kg  Certified limit  Operational margin kg.m  Operational limit 
CGcertified %RC  H-armcertified m  Moment kg.m  Moment kg.m  H-armoperational m  CGoperationa l %RC 
37320  15  18.431  686 168  -5 296.33  691 465  18.573  18.393 
53000  15  18.431  976 818  982 114  18.530  17.383 
63000  17  18.514  1 166 406  1 171 703  18.598  19.005 
72000  17  18.514  1 333 036  1 338 333  18.588  18.754 
73500  18.9  18.594  1 366 664  1 371 961  18.666  20.618 
15% 17% 19% 21% Operational margin Moment WeightCertified forward limit Operational forward limit  H-armCertified = (CGCertified x 0.041935) + 17.8015 MomentCertified = H-armCertified x Weight Moment0perational = MomentCertified . (-5 296.33) H-armoperational = Moment0perational / Weight CGoperational = (H armoperational . 17.8015) / 0.041935 

The complete computation leads to the determination of each individual operational limit. 176
Getting to Grips with Aircraft Weight and Balance

C. BALANCE CHART DESIGN

In Flight limits Takeoff limits

Landing limits

Operational Limits On the balance chart the 3 operational limits . Takeoff, Landing and In-flight . are not represented because if the Takeoff CG position check against its corresponding limit can be done after a manual or computerized computation, the determination of the Landing CG and furthermore the In-flight CG positions on a paper document is much more difficult, it is hardly possible to check these CG positions against their corresponding CG limits.
So only a Takeoff limit is drawn on the Load and Trim Sheet, this takeoff limit is the more limiting one of the three operational limits, depending on the values of each operational margins.
Note  often on A320 documents the forward In Flight limit is more limiting than the Takeoff one. And this specially for low aircraft weights. So the forward operational limit published on the balance chart or in the AHM560 is made of part of the In Flight limit and part of the Takeoff limit.
WEIGHT AND
BALANCE
WEIGHT AND
BALANCE
C. BALANCE CHART DESIGN

3.9. Zero Fuel limit determination
3.9.1. Definition of the Zero Fuel Limit
On the balance chart it is necessary to check the Takeoff CG position against the Takeoff
operational limit, this ensures that the aircraft CG position is within the certified takeoff limit.
Nevertheless this check is not sufficient to ensure that the aircraft CG remains within the in flight
and landing limits during the whole flight.
This second check cannot be made easily by checking the landing CG position and the different
　
中國航空網 m.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：Getting to Grips with Aircraft Weight and Balance(82)