The Tail must push down at all flying speeds to keep the a/c flying level, and not nosediving. With a T-Tail, at Stall, the a/c can pitch down without this downforce. If the Tail Stalls, the Tail must be flown with a pull to arrest its Stall, then a normal recovery. Let's see, do I have this right? The Tail flies opposite the wing, the lifting surface is the top, not the bottom. Anyway, I rue the attempt to eliminate the use of a perfectly good aviation word (incidence), by combination with its trained for alter ego, AoA.