heli's are so mega complex - it'd be such an insult to call em morons -lol-
the auto rotation works like this....

The main rotor blade's 'pitch' is adjustable in CP heli's - this makes the chopper go up and down when input is switched either way....
If your engine cuts in the air with a nitro heli - you give input to bring the heli toward the ground - gaining rotational speed in the main blades - as you get close to the ground - you give opposite collective input - as if to make the chopper fly up - this gives just enough power to make a smooth landing ;)

I've seen a video where a guy cut the engine wayyyy up in the air, came down UPSIDE DOWN - and got about 4ft from the ground - flipped the heli back upright - then landed so softly, it was incredible!