Carenado V35B Bonanza Autopilot Help With VS

[TheOtherJake]

Hello all, I'm trying to figure out how to use the Bendix King KAP150/KAS 297B in Carenado's Famous Flyers Beech Bonanza V35B in order to set a desired altitude, set a vertical speed of my choosing, and then have the plane fly to that altitude at the desired vertical speed. I have read the Bendix King manual and watched videos of IRL demonstrations but one specific thing in the Carenado plane is not working the way the manual and videos show: **Whenever I push the ARM button, the autopilot immediately sets a 500 FPM vertical speed rate up or down no matter what, and immediately starts climbing or descending.**

As I understand from the manual and videos, choosing an altitude and then pushing ARM should only tell the autopilot to be ready to capture that altitude when you get close to it - it should not automatically begin a climb or descent. However, that's exactly what happens: an immediate climb or descent at 500 FPM. This happens whether the VS is set to 0, or whether the VS is set to a number of my choosing, and whether the plane is level or climbing or descending - as soon as I choose an altitude and push ARM, it overrides all of my previous VS inputs and goes straight to 500 FPM up or down.

I want to be able to choose an altitude, ARM it, choose a vertical speed, and then engage that vertical speed that I want to reach the altitude and have the autopilot level out at that altitude. I believe this is the way it's supposed to work, but as soon as I push ARM - here comes 500 FPM. Is this a bug or am I doing something wrong?

Examples of what will happen:
- I am flying straight and level at 3000 ft and decide to climb to 4000 feet at 300 FPM. 
- I select 4000 feet on the KAS 297 B
- I select 300 FPM on the KAS 297 B
- I push ARM - the plane immediately starts climbing at 500 FPM and the KAS 297 B shows 500 FPM

OR 

- I am flying straight and level at 3000 ft and decide to descend to 2000 feet at 300 FPM
- I select 2000 feet on the KAS 297 B
- I push ARM - the plane immediately starts descending at 500 FPM and shows 500 FPM

So I'm not able to choose a FPM beforehand, and even if I do, the autopilot just overrides it and goes 500 FPM no matter what, and immediately starts a climb/descent on ARM push. Thanks for the help!

[Ernie Ball]

Hi Jake! ,

Just curious, did you get to the bottom of the workings of the V35B's AP ? 

I Just purchased this aircraft when it was on sale a couple of weeks ago, and tested it once only, recently, and found it difficult to use the Ap's Pre-select & VS!

David.