I had a DE tell me recently that the reason the flaps in a 172 have a placard that says "avoid slips with flaps extended" is because you have an increased liklihood for a tail stall. First question, is this true? Second question, what is a tail stall? I feel kind of ignorant asking this but I did some looking and although I find mention of tail stalls, I can't find a good definition of one. Is it a stall that effects the entire tail (otherwise, would it be called an elevator stall)? What is recovery like?