21stCentury, I guess that gets to the crux of my question: What happens *after* the V-22 gets back in helicopter mode? And where does that occur in the approach process? How soon before landing does the V-22 have to be reconfigured? And from that point on what is its airspeed and rate of descent? Can a '53 beat it in - guns a-blazing - from there? Or are they the same? As much as I admire and trust SASless's observations, in this case they're hardly scientific, and he wasn't in the LZ but out on a boat, no?
The fact that the V-22 is "quieter" as it approaches does not mean that it is completely silent or that it'll blend into the cacaphonous desert background noises or that it won't echo off the mountains. Even a caveman is going to be able to hear it coming at some point - maybe soon enough to pick up his AK-47 or RPG and go meet it?
I was at a Naval Air Station on the U.S. east coast some time ago when a CH-53 was doing autorotations. I stopped and watched because I could not believe what I was seeing. CH-53 autorotations! (No, not touchdowns.) I remember thinking, "That is one agile, manoeuvreable bastard for being as big as it is! I'll betcha you could ROLL that thing!"