AeroCruze100 (ALT pre-select issue)

[SaltyPIC]

Hello team,
We had the CenturyIIB and associated hardware removed, and the AeroCruze100 with its servo bundle installed in a Piper Cherokee. The initial altitude selection seemed ok, but sometime later in flight, when ATC assigns a new altitude, I have to do some major spinning of the knob to get to get the new altitude set down from some ridiculously high value. What kind of witchery is this??? Has anyone experienced something like this? It was suggested I send the control head to Mid-Continent. However, their techs are allegedly unable to reproduce the issue . I've attached a "normal" and "abnormal image" for reference.

Any thoughts? Thank you.

 

[Jesse Saint]

We have seen this when pitot and static were backwards.

 

[SaltyPIC]

Oh my goodness! Seriously? The installers did not even test/verify. Just said it's a device issue. Wow. Definitely makes me wonder what else might be amiss...Thanks J.

 

[Jesse Saint]

You can test it by pulling up the altitude sync on the ground and have someone suck on the static port. The altitude should increase. If they gently blow on the pitot the auto pilot should show Low AS, then normal, then High AS as they increase the pressure. Make sure they just blow gently on the pitot, because otherwise it could damage the altimeter. It's safer to suck on the static port a little.