How to enable ALT hold mode and what is SPUU?

[ebabil]

I am trying to learn its autopilot. But ı am unable to turn the ALT hold on by pressing

also in which scenarios should I use SPUU ? what does it do?

[Sacarino111]

HI.

The ALT autoplot is  working ok. You have to understand that it will do "some of the work", not all. You have first to be at a reasonable level flight/hover, with little to no  oscilation in altitude, and then you enable it, and don't touch the collective, or it will self disconnect the moment you add some little variation to the collective.

The trick is to enable the controlers view (CTRl+ENTR) and check its channel. If the line is over the center, it means it is "trying hard" to keep the altitude. You should add a lilltle bit of collective and re enable it again. If below, then you had too much collective at the moment when you enabled it, so it is trying to "take some work out" from the engine /collective. Reduce collective and re enble autopilot.

IF you wnat to hover, first reduce horizontal speed to almost zero, then enable the auto hover and then the altitude hold (the one for hover not for flying, with the small square in the picture you uploaded.)It will do an outstandong job keeping the thing stable in place.

About the SPUU (¿?), I can't tell; I activate it at start up and forget about all flight...

Saca111

Edited June 21, 2022 by Sacarino111

[admiki]

SPUU is a system that, based on environment, will limit how much right pedal you can apply, to avoid overstressing the tailboom. It takes about 3% (this is just my guess based on observing controls indicator, so if you need all the pedal, keep it off.

It's a bit more involved than that, but that's the short version.

[AeriaGloria]

On 6/21/2022 at 11:16 AM, ebabil said:

I am trying to learn its autopilot. But ı am unable to turn the ALT hold on by pressing

also in which scenarios should I use SPUU ? what does it do?

You can scroll down the page of the main forum or second page or so and you will see a thread by me with an autopilot guide. That will help with everything. I will link it here, scroll to bottom post 

but in short, 
 

What hasn’t been mentioned there is two altitude holds. In the bottom row on the right you have a circular button that is on in your screenshot, that is “barometric” altitude hold, it will hold altitude based off of barometric altitude and can be turned on in any flight mode as long as collective stays still and will work right if VSI is very close to 0.

What you are trying to press, the rectangular button on top as part of tue more advanced AP Functions, is a “Radar” altitude hold. This only works if hover hold is turned on first as the other poster mentioned. And thus can only be used below 50 kmh ground speed and best work in a hover. 
 

The SPUU is always on real life, as Miki said it limits tail rotor authority to not over stress the tail boom. This is not a worry in DCS as you can’t damage the tail boom, but I keep it on personally for both realism and if you fly with it off, you might have more right pedal authority but right pedal will also drain more power at max deflection, causing generator outage and such. Depending on temperature and altitude it will limit max tail rotor pitch from its max of 26 degrees to 21 degrees. It doesn’t affect left pedal with its max of 7 degrees. I believe all the way left on the spindle adjustment dial is no limit, and I think as Miki said, if you have the R control + enter menu up, the SPUU-52 limiting right pedal will be shown in the control menu as a small mark on the right pedal line, showing how much it is limiting right pedal compared to max right pedal 

Edited June 23, 2022 by AeriaGloria

[ebabil]

Thanks guys. These replies are very useful for me