G5 AI converter to drive century IIIC?

Discussion in 'Avionics and Upgrades' started by aiu0462, Sep 28, 2018.

  1. aiu0462

    aiu0462 Filing Flight Plan

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    Any chance Garmin G5 AI will be able to drive a a Century IIIC? May have to do Aspen.
     
  2. bnt83

    bnt83 Final Approach

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    No.
     
  3. flyingcheesehead

    flyingcheesehead Touchdown! Greaser!

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    No. The G5 AI does not feet attitude to any autopilot, so if you have an attitude-based autopilot (as opposed to rate-based ones like S-TEC), you need to have an attitude source that works with your autopilot.

    The G5 HSI with the GAD29B can drive the HDG and NAV modes of compatible autopilots, and that list is pretty extensive.
     
  4. bradp

    bradp Filing Flight Plan

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    The only thing you could do is move the CIII AI to the turn coordinator position and keep it in the panel as long as it doesn’t have a flight director.
     
  5. Clip4

    Clip4 En-Route

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    For enough money I can integrate an old Western rotary phone to your smart phone, but you still have obsolete equipment.

    upload_2018-10-9_7-29-0.jpeg
     
  6. Russell MacDonald

    Russell MacDonald Filing Flight Plan

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    As you may know, the G5 interfaces to many different analog autopilots using the GAD29B converter. I have copied only the Century autopilots that will interface from page 128 of the G5 installation manual:

    *** Quote ***
    5.15 GAD 29B Interface to Non-Garmin Autopilots

    This section only applies to installations using a GAD 29B data converter and an interface to
    one of the autopilots listed in Table 5-1.

    Table 5-1: Non-Garmin Autopilots

    Century 1C388*
    Century 1C388M*
    Century 1C388C*
    Century 1C388MC*
    Century 1C388-2*
    Century 1C388-3*
    Century 2000
    Century 21
    Century 31
    Century 41
    Century IV
    * Radio Coupler P/N indicated and based on aircraft installation
    could be interfaced in a Century II or III.
    *** Unquote***

    Russ
     
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  7. flyingcheesehead

    flyingcheesehead Touchdown! Greaser!

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    What you're missing is that these autopilots interface to the G5 *HSI*. The G5 *AI* does not supply attitude information to any autopilots at all, so if you have an attitude-based autopilot, you need to keep your existing AI and its power source, which kind of defeats the whole purpose of the G5 for many of us. In my case, we have an aging KI-256 that occasionally decides to get a little lazy on a long flight, hooked to a KFC 150 autopilot. Our only options for replacing the KI-256 are to put in an overhauled KI-256 (and keep the vacuum system), or replace it with an Aspen, G500, or G500 TXi. The KI-300 is vaporware, and nothing else will provide attitude to the KFC 150.

    At least they've now got the vaporware KFC-230 slide-in replacement to go with the vaporware KI-300 it depends on. :rolleyes:
     
  8. Unit74

    Unit74 En-Route

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    I talked to an Avionicss shop in Florida who said they have built some sort of device that will work with the AI autopilots for a sanitary G5 install. This was when I was shopping a G5.
     
  9. flyingcheesehead

    flyingcheesehead Touchdown! Greaser!

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    That'd be the GAD 29B converter - But that's what you need to hook the G5 HSI up to the autopilot, not the AI.

    If they certified the AI to drive legacy autopilots, it wouldn't cost $2K any more. :(
     
  10. Russell MacDonald

    Russell MacDonald Filing Flight Plan

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    I understand the difference between a rate based and attitude based autopilots.

    What I don't understand is why Garmin lists the Century III as capable with the G5 HSI. Is the C-III compatible with the G5 HSI (and not the G5 AI)?
     
  11. bnt83

    bnt83 Final Approach

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    When you get right down to it, neither G5 AI or HSI display are compatible. The only bloody thing that can be hooked to a legacy autopilot is the GAD29B. The GAD29B outputs analog LH/RH error, that is all it can do for old autopilots. The GAD29B is included in the G5 HSI kit.

    The LRU part number of the "displays" provided in the attitude indicator kit are the same as the "displays" provided in the HSI kit.

    If an autopilot depends on a legacy gyro, a G5 cannot replace that gyro. For example, a turn coordinator, my brittain uses a TC, G5 cant replace it. Century uses attitude gyros, G5 cannot replace them.
     
    Last edited: Oct 11, 2018
  12. flyingcheesehead

    flyingcheesehead Touchdown! Greaser!

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    Right. Via the GAD 29B, the G5 HSI can provide heading and track error to the CIII, and is thus "compatible" as an HSI. The G5 AI cannot provide attitude.

    That's a good point. For complete clarity - The G5 can actually replace your turn coordinator as well, but if you have a rate-based autopilot like an S-TEC or a KAP 140, you still need to keep your S-TEC turn coordinator. At least in that case you could still ditch the vacuum system.
     
  13. Russell MacDonald

    Russell MacDonald Filing Flight Plan

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    I understand what you are saying, and I am not an expert on the GAD29B. However, I have learned how it works in my plane.

    In my Cardinal RG, the GAD29B is used to generate the 'Heading' input for my STEC 30 autopilot. The Heading input on most analog autopilots was traditionally used for only the Heading Bug. However, the GAD29B receives Heading Bug data or GPSS data from the G5 and converts that to the analog Heading signal input to the autopilot. When I select GPSS mode on the G5, I have to also select the Heading Mode on the S-Tec 30 autopilot, and then the autopilot follows the GPSS signal. Then, I can switch back and forth from Heading Bug to GPSS without changing modes on the autopilot.

    In the S-Tec 30 system, the LH/RH Error signal comes directly from my GNS530W and goes ONLY to the S-Tec 30 autopilot. That signal can be either VOR/LOC or GPS depending on the mode of the GNS530. That signal does not go to the GAD29B and is not processed in any way by the GAD29B. To track that signal, I put the autopilot in Track mode.

    Have you seen the G5 Installation Manual? It is available on the Garmin site and has schematics for interfacing the G5's with several legacy analog autopilots including the Century autopilots.
    Hope I can post this link: http://static.garmin.com/pumac/190-01112-10_14.pdf

    Russ
     
  14. flyingcheesehead

    flyingcheesehead Touchdown! Greaser!

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    Yup - This is also exactly how S-TEC's own GPSS converter works. Put the AP in HDG mode, and then there's an external button that switches between HDG and GPSS. In the club, we got a lot of squawks where people thought it wasn't working right, because they were in NAV mode.