  :Aha, it’s an interesting problem! I understand better your edit now. We really need to write this article on Aircraft longitudinal equilibrium... :There are two distinct reasons why the CG may not coincide with the wing centre of lift.  :# As you explain, the wing centre of lift moves when equivalent air speed is varied, and when flaps are deployed (trim); :# Static stability is increased when the CG moves forward (stability). : In other words, even if the wing centre of lift did not move (say, a flapless wing with symmetrical profile) we would still want the CG ahead of the wing. Otherwise we would need a disproportionate (zero-lift) stabilizer to provide the required stability. That is the reason why airliners still generate negative tail lift in cruise, where the trim conditions are most favourable (high equivalent speed, clean wing). : So, does the wing centre of lift move ahead of the CG, or do we position the CG ahead of the wing centre of lift? Both, I guess =) In this light, I think each of our article versions is too categorical. I’ll try to find a better compromise, but feel free to edit right away.   