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Old 26th Jan 2012, 14:25
  #47 (permalink)  
keith williams
Join Date: Jan 2011
Location: England
Posts: 642
You need to understand the meanings of the various terms.

The MAC is the Mean Aerodynamic Chord Length.

The statement that
the MAC is given as 134.5 inches
means the distance from the MAC leading edge to the MAC trailing edge is 134.5 inches.

15% of 134.5 inches is 20.175 inches.

So if the CG is at 15% MAC it is 20.175 inches aft of the MAC leading edge.

If we now add the MAC leading edge poistion of 625.6 inches aft of datum we get a CG position of 20.175 + 625.6 = 645.775 inches aft of datum.
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