Hi, before i try this in real life, I would like to know how the helicopter should behave when I am in stabilize mode and cut throttle. So far I only know how it works in acro mode but would like to know if it is still posibile to control the heli in stabilize mode.
If I have an engine failure in loiter or auto mode, is there any way to safe the helicopter without switching to acro mode or maybe by switching to stabilize mode? I can not imagine how i could work in any mode where pitch is controlled by the flight controller and in stabilize I cannot imagine how the flight controller is still able to control yaw when not in fast forward flight. I am thinking about a case where I have high altitude in loiter mode and the engine fails. Normally I can switch to acro, accelerate (which goes fast in acro because I do not need to keep the elevator stick pushed) and land safe in autorotation.
Stabilize or Acro flight modes will be fine to perform the maneuver, the collective and tail rotor behavior will be exactly the same as if you were flying it as a traditional R/C helicopter .
Generally speaking, Stabilize flight mode will make things a lot easier:
the demo is very impressive, and the auto-rotation is so exciting.
do you have any documents for that how to set?
no sorry, I do not have any documents. The piloting procedure itself is very well documented anyway.
Regarding setup, as a starting point, you can use the following for main rotor head:
full collective pitch: +12deg
hover collective pitch (mid-stick on Tx side): +5deg
bottom collective pitch: -5deg
Before trying it, make sure pitch/roll and especially yaw actual angles match perfectly the desired angles.
For the yaw axis a proper check is to apply reasonably sudden collective pitch changes (both up and down) while hovering at safe altitude, tail has to stay still thorughout the maneuver (if not increase ATC_RAT_YAW_P). Then, again in hover condition, apply quick tail rotor inputs, tail has to stop without any obscillation when stick is centered back (if obscillation occurs increase ATC_RAT_YAW_D).
This is important for a stable autorotation-entry phase (so when you lower collective and cut power).
For the subsequent glide-phase the collective need to be around -2 deg, close to the lower quarter stick travel on your collective stick.
You will use your pitch stick to adjust speed/height, do not use collective.
Practice first ones on a smooth grass runway, always keep in mind forward speed is your friend .
Do a gentle flare saving some speed for the subsequent touchdown-phase, this will increase your time margin before touch down significantly, allowing you to use the minimum amount of collective pitch at the same time (so keeping a higher RPM, i.e. better stability and control at the touchdown).
I have no experience to the auto-rotation and you method is very useful