Originally Posted by
Luc Lion
This lift adds to the wing lift and thus increases the climb rate.
Sorry about that. I really feel ashamed to have stated that additional lift could help the climb. Not enough thinking before writing.
Yet, the positive influence of an aft CofG has to do with the transfer of lift from the wing to the elevator. At relatively high AOA (low speed), having part of the lift provided by the elevator (because of having an aft CofG) reduces the AOA of the wing and reduces the drag at the expenseof increasingthe AOA of the elevator and increasing the elevator drag. That can only be beneficial until the elevator D/L ratio becomes equal to the wing D/L ratio. The point where the D/L ratios of wing and elevator are equal may be outside of the CofG limits depending on the plane type. This can only have an importance at low speed, because it's the induced part of the drag that is influenced by the AOA.