Looking for a Century III A/P guru

Aviation chatter - For ALL Pilots and Aviation Enthusiasts

Moderator: Moderators

User avatar
Posts: 157
Joined: Fri Aug 17, 2007 8:33 am
Closest Airfield: FASH
Location: Somerset West
Has liked: 3 times
Been liked: 0

Looking for a Century III A/P guru

Unread post by FlyingFinn » Wed Aug 14, 2019 10:33 am


We have a Century III in our Baron 58
we would need to locate somebody who has a lot of experience in troubleshooting them
it works great other than that it does not want to hold the altitude, and by now we have replaced all the "obvious" parts

is there someone still around who can make this legacy a/p work as intended

pls don't respond by recommending to replace it with a half a million Rand Garmin :D

User avatar
Too Tousand
Too Tousand
Posts: 2581
Joined: Mon Sep 05, 2011 1:09 pm
Closest Airfield: FAWB
Location: Pretoria
Has liked: 25 times
Been liked: 40 times

Re: Looking for a Century III A/P guru

Unread post by Iceberg » Wed Aug 14, 2019 10:43 am

AME Aviation on FAWB did good work on mine. They serviced all the servos and set the AP. It works well when driven by my Aspen PFD.

Regarding the altitude hold, I've also had issues. Here is a piece I found quite useful:

Altimatic 111C adjustments

If the issue is always the same, level off, hit altitude hold and you climb, that is an adjustment that needs to be done in flight. Behind the faceplate on the CIII console are six recessed screwdriver adjustments. The first three (left to right) set the left bank limit, centering for the DG/HSI, and the right bank. The next three set the pitch down limit, the altitude hold centering, and the pitch up limit.

The fifth adjustment is the one that corrects for the altitude hold can. These are delicate 10-turn pots.

The idea is to take the faceplate off the CIII console, go fly with a safety pilot in smooth air, at the speed and loading conditions specified for your aircraft and engage the altitude hold. If the plane wants to climb or descend upon engaging the hold unit, you adjust this until it stays on the altitude you set it at when engaging the alt-hold mode.

With the proper tools and test equipment, this can be pre-set on the ground pretty closely. But the shop will need the test kit for Century autopilots, including the gyro substitute signal. A final adjustment needs to be done in the air.

If the alt-hold does different stuff all the time, then you have other issues at play. But if it consistently climbs or descends a little, then stays put, it is just the adjustment.

But you need to figure out what the flight conditions are, for your specific make and model of aircraft. There will usually be an airspeed and some condition of loading, like near aft CG, in the specific setup.

Hope it helps.
These users liked the author Iceberg for the post:
The sky is not the limit....
Karl Eschberger

Return to “General Aviation Chatter”