Originally posted by Johng
The spot at 25% MAC is the aerodynamic center of the WING. The neutral point of the airplane is the spot at which the CG location would result in a neutraly stable airplane - not self recovering, but not completely out of control. You don't want the CG at that location for the first filght.
The neutral point changes depending on geometry, most strongly the size and goemetry of the tail. I have a plane that has the neutral point at 70% MAC.
Oh, ok thanks I will check this out with that excel spreadsheet in time.