However, getting back to your original concerns, can you indicate the specific trimsheets from which you obtained your MAC values ? If the trimsheet is consistent with the Airbus calculation models then the reason for the apparent MAC difference should stand out.
In fact I obtain data (DOW and DOI) from Loadsheet gaetan , I Took It when I worked In Orly airport like Fligth dispacther.
So I prepared Two Fligth, one which have DOW = 44128 with DOI =27,1
and an other DOW =4378 and DOI=45,5
I noticed when I take paper trim sheet A320 from company alpha I can't use it for all A320, in fact for the first plane (DOI 27,1) le LITOW is out.
So I deduct each company have his owner trim sheet, but there must be an generic equation which give %Mac for all Airbus or aircraft.
I have a doubt about this equation % Mac =100*C*(I-K)/Weigth*Length of RC + 25 and I have a doubt about 25, I think this value is result of this equation :
100*(Harm -hH25)/Lenght of Chord
PS: I ma sorry if I repeat myself, but I'm very perplexed about determination % MAC,
I Continue the research
thank you