QAYS,
Good to have you on board .. don't worry about your English .. your English is far, far better than my long-forgotten schoolboy French.
You have posted an unusually complicated formula for %MAC. I think that we need some more information before we can make some sense of it. Can you advise what the following terms are (ie what do they mean in physical terms) ?
(a) C
(b) LIZFW
(c) K
(d) Chord (ie which particular chord ?)
(e) Harm (perhaps distance from OEM FS datum to CG location ?)
We could run some reverse engineering to relate it to the standard equation but, if you can provide the above information, it will save some time. Indeed, without the information, we can't even begin with a dimensional check of the equation.
regards,
John