Really??? I've read a lot of posts of people saying they love to engage the Alt Hold and navigate on their own...I don't know what to do...
OK, if you are set on using one servo only - then let's go about it in a sensible way.
If your aircraft trims and holds pitch nicely and you are OK with the idea of having to retrim every once in a while, then it would be fine to install the roll servo.
Even with a very stable roll, no aircraft will hold a heading for long - it is guaranteed to start drifting this way and that way - in particular if you add a bit of turbs - so it makes sense to use the roll servo.
If your aircraft does not hold pitch well (like our's for example) then having the pitch servo is a must or else you will still need your hand on the stick (and that kinda is not what an AP is all about).
Having a roll servo but no pitch servo seems sensible (if possible) but I can't get comfortable with pitch servo but not a roll servo. I know, not all aircraft are created equal so there may not be a correct answer.
I guess, you could fit the pitch servo and then use the rudder for small corrections, this way leaving the stick alone - that would work in our aircraft...
In any case - make sure you can install the missing servo at some other time because I am pretty sure that is what you are going to do sooner or later...
Rainier
CEO MGL Avionics
