Altitude Autopilot

Hey guys - i think this may have been asked, but i couldn't find an answer. Is the altitude autopilot supposed to only adjust the collective down, and not up? Because that's how it's working for me. If i'm in a decent and i activate altitude autopilot, nothing happens.

If i'm climbing and activate it, it'll collective down, but what usually happens is it will collective down too much, putting me into a descent that it won't recover from since it won't collective back up. hmmm

thanks for any help!

-D

Mi8 autopilot is weird. Sometimes it works lie a charm, sometimes its like rollercoaster ride, up and down. Chopper wants to kill you, its insane and so frustrating to fight controls on a 30-45min trip and compensate forward flip suicidal intentions. What is wrong with Mi8? Also what is the relation between trim and autopilot, is that correlated? Any specialist here?

my experience is that it works fine up and down, if the collective is in a position to allow it enough authority to do its job when the AP is set...

Works well enough to go make a cup of coffee anyway...

Did you assign the altitude using the altitude assign lever?

my experience is that it works fine up and down, if the collective is in a position to allow it enough authority to do its job when the AP is set...

 

Works well enough to go make a cup of coffee anyway...

I Agree with this and have seen it often, as long as the collective is set to a good value for the attitude being flown then the Altitude AP adjusts up and down.

Too low a collective and the AP only goes down only, this is my observation.

Did you assign the altitude using the altitude assign lever?

The altitude is assigned when you press the altitude channel button on the autopilot panel.

EDIT: I should point out, in case it wasn't obvious, that there is no altitude assignment lever on the Mi-8. The only way to assign an altitude is by engaging the autopilot using the button on the control panel.

Before activating level AP you need already be in aproximate level flight. It have limited authority indicated by white bar on its gauge. So you need to be that much in level flight that corrections needed will not be greater than its limits. Otherwise it hit limit, and disengage ( without indicating it :P)

Works well enough to go make a cup of coffee anyway...

Half the fun of long XC flights in the Mi-8 is being able to still get the lawn mowed haha.

So put in simple terms:

Reach the desired altitude and stabilise.

Gently move the collective up and down and find the centre point between where she climbs slightly and descends slightly.

Set that centre point and engage the altitude AP.