Lyman, I cannot cite this b/c I'm an airhead with few remaining memory cells, but, I am sure that I have read in an AB publication on control laws that the ND input must be definite and prolonged before the AC will trim accordingly. I'll look for it in my mahssive collection of documents. I think you should give up on this line of speculative inquiry. Ppl been telling you repeatedly that Bonin's ND inputs weren't enough to do it. No hidden conspiracy there, I accept it as fact.