ORIGINAL: foxx
The CG machine makes you to balance the plane upside which normally do not fly that way.
The CG machine makes you balance the plane in its most unstable configuration, ie, worst case scenario. So if the plane flies right side up, it is guaranteed to be more stable. Plus, if one decides to fly inverted, then one would rest assured that the plane will have no problem doing so. All low wing planes should be balanced inverted. Nuff said.