G5 Operating as a DG

Discussion in 'Avionics and Upgrades' started by Rob58, May 15, 2019.

  1. Rob58

    Rob58 Pre-takeoff checklist

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    I'm trying to understand how an electronic (non-gyro based) DG instrument such as the Garmin G5 determines and maintains heading information when it is not paired with a magnetometer. Does it require the heading to initially be set as does a mechanical gyro type instrument? Once set does it need periodic adjustment? Is it really accurate to refer to a device like this as a "DG"? Just trying to understand the theory of operation... thanks!
     
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  2. bnt83

    bnt83 Final Approach PoA Supporter

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    You cannot install a G5 as a DG or HSI without a magnetometer, per STC limitations. There is no setting of initial heading, the system is an electronic compass and electronic solid state gyro and does that by itself.

    If the GMU drops offline heading is gone, replaced by GPS track. If both GMU and GPS drop out, pretty sure you got nothing on the DG/HSI
     
    Last edited: May 15, 2019
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  3. JohnAJohnson

    JohnAJohnson Cleared for Takeoff

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    I am interested in a G5 HSI too (STC version). If I install it now, I wonder if I can send it to Garmin in a year and get it changed to an AI for a reasonable price. Anyone know?
     
  4. Groundpounder

    Groundpounder Line Up and Wait

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    I don't think you have to change anything, you just switch it to ADI mode. I am getting a G5 installed as an HSI on my airplane, and it will also function as a backup ADI.
     
  5. bnt83

    bnt83 Final Approach PoA Supporter

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    Sure you can use it that way without even returning it to garmin but you'll end up with a HSI peripherals doing nothing. The screens are the same part number between the ADI and HSI, the softwares are identical, it's how they are setup to operate in the configuration menus that defines what they do, which is easy changed by the installers.

    If you were upgrading to a G3X from a single G5 installed as an HSI none of the equipment would be removed, just rewired a bit, possibly some other changes, but none needs returned to garmin
     
  6. JohnAJohnson

    JohnAJohnson Cleared for Takeoff

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    I'm getting ready to install a new radio stack and I won't have a CDI or HSI to display nav data from my Avidyne IFD540. I eventually want to install the Dynon Skyview system, so I don't want to spend money on a GI-106 or other device that I couldn't make use of long term. My thinking is that once I get the Skyview, which requires a D10A for a backup attitude indicator, I'd still like a second nav head, and a third attitude display. And I think the G5, ordered as an HSI, should be able to do that.

    I'd appreciate input on my thinking and on alternatives, if any.
     
  7. SloRoam

    SloRoam Filing Flight Plan

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    The g5 can be configured to start in ai or dg mode. This is covered in the installation manual.

    That said, I would not buy the g5 as the ifd will show the same info on its screen I think... Best to verify what you need especially if you are ifr..
     
  8. Jesse Saint

    Jesse Saint Pre-takeoff checklist

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    The IFD will not display the same information as the G5 HSI. It’s not a bad plan to add the G5 HSI to the IFD, then use it as a third attitude display when you add the Skyview.
     
  9. JohnAJohnson

    JohnAJohnson Cleared for Takeoff

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    Thanks all.

    One other question... My second NAV COM is TBD, but it'll probably be either an SL30 or a GNC 255A. Can the G5 HSI software select either the IFD540 or the TBD radio for its source, or would there need to be an external switch? I've read the installation manual but this isn't clear to me.
     
  10. Jesse Saint

    Jesse Saint Pre-takeoff checklist

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    In a certified plane it can only be one or the other permanently.