Stepping on the wrong pedal will get your nose to "tuck" under! That is for sure, since one of my students showed me that once!
Otherwise, apparently, the Upper Canopy Slat as it is called, is to smooth out the airflow to the tail rotor, and not so much about the nose tucking under. The nose on any helicopter I believe will pitch down during entry into an autorotation, also true in H269's and this is corrected by applying aft cyclic. Hence when I teach my students autorotations the littany is: DOWN-AFT-RIGHT for down collective, aft cyclic and right pedal to get the auto going. simulteneously of course (opposite on those machine with the blades turning the wrong way
). Hope this helps somewhat.
By the way, if you want, go to
www.ntsb.gov and search under accident investigation to find how many H269 accidents there are. not very many if you compare to some of the other light machines!