Throttle hold is a function of engine failure "simulation" in order to practice autorotations. By using throttle hold you can hit the switch and the throttle will go to a preset position, for example near idle, there by allowing the immediate execution of a practice auto. Throughout the pitch pull with the throttle hold on, the throttle maintains it's position. You can also practice "hover autos" with the throttle hold.
A auto-rotation means no motor. The throttle and blade control are on the same stick. The throttle hold allows the motor for (glow to stay at idle and still stay running, like neutral in a car) (elec turns off motor) all while still having control of the pitch of the main blades. Just as if your motor really dies. I am glad I practiced that in a stable condition because one time it did die and I knew what to do and saved my heli!
I'm still new to autos, But twice I've had to learn fast when my engine quit while in flight. Both landings were rough, one result in a tail strike, the other, a lot better. A few small parts broke, but nothing serious. Haha, in other words, my T-rex 600N was like, "You're gonna learn today!" XD
Well in the old days (80's) you would go slightly neg pitch to build up kinetic energy on your way down. Much depended on how much forward speed you had when your engine failed (or hit hold) as forward speed make things even easier. Around 15-10 feet or so you would start to slowly go positive, The trick was not to go full positive abruptly or you would go into a hover at 10 feet then drop like a rock. I see from some of the comments that people think this is something new,
Wish he'd demonstrated with a 450 or even 250 size helicopter. 600/700 nitro's land itself. I use Curtis Youngblood's method of flaring down sideways. Keep's tail blade off the ground.
So to do it what is the process, is it that you engage throttle hold and then movet the throttle stick down a little to cause the blades to spin and then move the thottle stick upwards to create some lift when almost to the ground?
Is this considered a big deal with electric models? I have never done 3D yet auto'ed just fine the time I tried-I had no choice when my clutch burnt out around 150ft or so. About 10 feet or so I started adding positive pitch and flaired it just fine. Thinking about getting back into the hobby with a small model (maybe the 300x?) and just wondering why this crowd acts like it's a big deal when it was very common back in the 80's. What little I know about 3d seems much harder than autorotation.