[mikeash]

Oh nice, I didn't realize TCAS was available there.

As for autorotation, my worry isn't so much the procedure (although it sounds much trickier than a gliding landing in an airplane) but the fact that you don't get much horizontal maneuvering and there aren't many good places to land in a dense city, and the fact that there are many single points of failure that make it much more likely to happen.