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Practice Exam Question - ECHO

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(@user5843)
Eminent Member Customer
Joined: 15 hours ago
Posts: 21
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Given:

An Echo is loaded with the main tanks full and the auxiliary tanks empty.
The gross weight is 2550 kg and the total moment index at that weight is 682 index units.
The greatest amount of fuel that may now be loaded into the auxiliary tanks is closest to:

[code]ZFW 2278 2781 633.6
Main 272 1780 48.4
Aux 2800 0.0
Gross 2550 2675 682.0[/code]

To move the Gross weight from 2675 to the limit of 2680 it worked out
5.5mm x 2550 / (2800-2680) = 116.87

Which was the suggested solution

I am concerned however that the ZFW limit of 2781 is well outside of the CoG range. As the AUX tank is outside the CoG range, no amount of fuel will bring the CoG forward into the range.

I am hoping that I made another silly mistake here.



   
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Bob Tait
(@bobtait)
Illustrious Member Customer
Joined: 16 years ago
Posts: 2538
 

Yes, you are quite correct. If the CofG condition with the main tanks full was 2550kg and 682 the actual ZFW would have to be way outside the aft limit that means the aircraft would burn itself out of the aft limit as you burnt the main tanks. The question needs rewording. Congratulations! I'll make some changes to the wording of the question. Well done....



   
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