ORIGINAL: BarracudaHockey
The helicopter does NOT spin smoothly to the ground in an auto, nor does it do its own auto if you turn off the transmitter.
You need negative pitch to do an auto with a model. There's a point on every heli that depends on blade weight, airfoil, helicopter weight etc that you need to find, any less negative and you loose head speed, any more and you only fall faster without gaining head speed.
As for MX400's and lighter electrics, they auto like a brick.
Ha, yep. With a mini the only way to tell a successful auto from a crash is that the pilot isn't swearing (usually) and not a lot of stuff breaks (usually, unless the pilot is swearing).
I expect that it's a pretty puckerful maneuver even in a full-sized helicopter.
By the way, I have watched people do this, but I don't do it myself IRL. Practice on the sim is enough for me, just in case. The only time I've had to auto was from about four feet up, and that just needed the flare, not the autorotative descent-- and the descent is what takes skill.
If anyone's curious, the way it works is that with some negative pitch on the blades (as BH pointed out above, finding how much is difficult), the inner (slow moving) part of the blade stays stalled, the middle portion is driven by the upward flow and keeps the blades moving, and the outer, fastest moving part actually keeps flying and generates lift for control during the descent. Pitch and headspeed control the size and location of these zones on the blade. You might guess from that the reason that it's difficult-- that's a very fine balance to maintain, and you only have a few seconds to establish it between when you're up there and when you're down here.