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ZFWCG Calculation

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I am going to try explain how calculate the ZFWCG. It is something difficult because in the Flight Simulator there is some data that we can not get.

Ok, we must know that it is the 'DATUM' for calculate ZFWCG. The DATUM is an imaginary vertical reference plane or line chosen by the aircraft manufacturer from which all arms used for weight and balance computation are measured.

In the next image we have all necessary measures to calculate the ZFWCG:



Ok, We calculate ZFWCG with the next equation:

        ZFWCG = D - F*L/ZFW


D = Distance from Datum to Main Wheels, it would 2,3M + 17,6M = 19.9M

F= Net weight Nosewheel, this date we haven't it in Flight Simulator, suppose it is 7.000 kg

L= Distance from Nosewheel to Main wheels, it would 17,6M

ZFW= 42.000 kg

  ZFWCG = 19,9 - 7.000*17,6/42.000

  ZFWCG= 17 meters from Datum.

Ok, now we have to convert in % of MAC (Mean aerodynamic chord) for this we use another equation:



 ZFWCG% = CG from LEMAC * 100/MAC in meters


CG from LEMAC(Leading edge of the mean aerodynamic chord), it would 17M-15M = 2M

MAC would 22M - 15M = 7M

  ZFWCG% = 2*100/7

 ZFWCG% = 28,5%

For me this is very dificult to calculate in the Flight Simulator because some date as LEMAC and TEMAC distance and net weight nosewheel we haven't it.


Edited by Monty43

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