Genghis.
Might I suggest that you stop playing with equations. They are actually irrelevant unless you know the type. In this case the 747/200. LOMCEVAK does as does 747FOCAL. I don't, but it is a waste of time going through something which has no relevance. Especially as you admit you have no knowledge of the type.
As far as I am concerned the question has been very well answered - even I understand.
Light aircraft are light aircraft, your particular field. Leave the heavies to those who know.