Just out of interest, I've used the sideways q-stop from around 50-60 knots as an opening manoeuvre for my standard display for some 35 years. (1245 public displays) Even the large airframe area Enstrom 480 and 280 series handles the manoeuvre without difficulty. Perhaps the sideways disc angle achieved is the factor since, at say 45 degrees, it would seem the reversed relative airflow is similar to an autorotation entry. Dennis K