Mad Flight Scientist, the purpose of any side slip is not to give maximum rate of descent, it is merely used to increase ROD while limiting airspeed, and in a variety of types it aids forward view. With the greatest of respect therefore, I suggest that your scenario of an emergency descent is an unlikely use of the manouvre.
Clive Watson, MFS certifies transport aircraft he knows all about that stuff:
Guppy, that post was eye opening,... I think that post would be helpful for the CFI's I work with,...and perhaps only ONE ED and slip to land. one visit to the practical slip limit is enough for every student
You mechanics must sometimes think pilots are a little thick
PA