Forget the concepts of "Non-Precision" and "Precision". Because there are now approaches that are flown "similar" to an ILS eg LPV, GLS, Baro VNAV, RNP-AR ie they give proper, legalised vertical commands which you must follow (like you follow a GS), the old "precision" concept ie provision of a GlideSlope, has become muddied. That's why the system introduced 2D (2 dimensional, the old MDA-type approaches) and 3D (approaches flown with vertical guidance/commands ie 3 dimensional that include ILS and RNP-AR and indeed BaroVNAV. All 3D approaches are the same: follow the pitch commands down to the DA and then go around if not Visual.
FD, an "APV" is an
APproach with
Vertical Guidance", a 3D approach. Flown exactly like an ILS, but obviously not one, in the historical sense of the "precision" concept. The "BARO" part signifies the altimeter/QNH is being used to provide vertical commands, as opposed to a GLS, where I assume the GPS gear is used to provide the "glidepath" to follow. An RNP-AR would therefore be a type of Baro-VNAV, I suppose, which is of course an APV!
