jliltd
Well Known Member
As far as access for maintenance, you might be surprised how much access the large EFIS screens give once removed.
Whether you do or do not go with a more modular removal-friendly panel design consider making mounting plates for each engine control and any other penetrating cable that would normally have to be pulled prior to panel removal. These mounting plates are basically round panels with a diameter larger than the knob for each each push/control. The control cable is mounted in the direct center of the mount plate and the mount plate is attached to the panel from behind with 3 nutplates or can even be machine thread tapped if thick enough. The plates can be a flush fit or an overlap. So when you decide to pull the panel you only have to unscrew each control mounting plate and the panel will come out with the holes sliding over each control. This keeps you from having to disconnect all the push/pull cables from the throttle, governor, mixture, cabin heat, cabin air etc and then remove each through the firewall prior to panel removal. And then later having to re-install and re-rig these controls after panel reinstallation. They just hang around with their mounting plates until re-installed in the panel.
And speaking of the throttle. I prefer the push/pull for it rather than vernier. Just like you show in your design. A vernier control is fine for prop and mixture but vernier on throttle can have some safety issues. One of the reasons most formation clinics and formation instructors won't allow vernier throttles in participating aircraft. Your friction lock works just fine for throttle and allows pilot full and quick control of throttle without having to fight the vernier release in a panic situation.
I also like your choice of the GTR 200B for VHF com. They are awesome and the built-in stereo ICS is fantastic. Too bad they are so deep. If and when the time comes to add a GTN or similar IFR navigator you will require an audio panel to do the switching at which point the GTR 200B ICS and Bluetooth will become inactive. But in the meantime you have chosen a very simple and practical approach with the 200B.
Here is another vote for a aera 660 either surface mounted or flush mounted in the center stack. I would pair it with a GDL 52 and feed the GDL data to both the GDUs and the aera 660. The 660 has a great backup battery, as does the GDL 52 so in an emergency this combination will give you navigation and a attitude indicator with synthetic vision to get you to an airport. The GDL 52 has basically obsoleted the need to pay extra for a GDU panel with built-in SXM.
As mentioned in other comments, please remote mount the GSU 25 units. They not only don't play well with vibration mounted to the GDU screens they add complexity to the screen removal process. You will be surprised how often you will remove the GDU's to gain access to the rest of the panel during maintenance and it isn't a good idea to remove and reinstall pitot and static lines or have to unscrew the whole GSU 25 just to remove the screen.
And finally. The G5 is a fine backup. There was mention of software/manufacturer independence with respect to backups for glitch resistance. Realize that Garmin purposely had a dedicated team design and program the G5 so that there was no commonality between it's firmware and software and any other Garmin product. Meaning the G5 is every bit as independent as backup EFIS offerings from other manufacturers with the added feature of playing well with the rest of the panel via CAN Bus. In the final analysis for most flights your G5 will be a very nice fixed barometer setting knob for the whole G3X system. And having that knob is remarkably convenient I must say. Not $1200 convenient, but convenient. However, that day when the G3X goes black the balance of the G5 cost investment comes into play, which is the basic mission of a G5 in a G3X system.
Jim
Whether you do or do not go with a more modular removal-friendly panel design consider making mounting plates for each engine control and any other penetrating cable that would normally have to be pulled prior to panel removal. These mounting plates are basically round panels with a diameter larger than the knob for each each push/control. The control cable is mounted in the direct center of the mount plate and the mount plate is attached to the panel from behind with 3 nutplates or can even be machine thread tapped if thick enough. The plates can be a flush fit or an overlap. So when you decide to pull the panel you only have to unscrew each control mounting plate and the panel will come out with the holes sliding over each control. This keeps you from having to disconnect all the push/pull cables from the throttle, governor, mixture, cabin heat, cabin air etc and then remove each through the firewall prior to panel removal. And then later having to re-install and re-rig these controls after panel reinstallation. They just hang around with their mounting plates until re-installed in the panel.
And speaking of the throttle. I prefer the push/pull for it rather than vernier. Just like you show in your design. A vernier control is fine for prop and mixture but vernier on throttle can have some safety issues. One of the reasons most formation clinics and formation instructors won't allow vernier throttles in participating aircraft. Your friction lock works just fine for throttle and allows pilot full and quick control of throttle without having to fight the vernier release in a panic situation.
I also like your choice of the GTR 200B for VHF com. They are awesome and the built-in stereo ICS is fantastic. Too bad they are so deep. If and when the time comes to add a GTN or similar IFR navigator you will require an audio panel to do the switching at which point the GTR 200B ICS and Bluetooth will become inactive. But in the meantime you have chosen a very simple and practical approach with the 200B.
Here is another vote for a aera 660 either surface mounted or flush mounted in the center stack. I would pair it with a GDL 52 and feed the GDL data to both the GDUs and the aera 660. The 660 has a great backup battery, as does the GDL 52 so in an emergency this combination will give you navigation and a attitude indicator with synthetic vision to get you to an airport. The GDL 52 has basically obsoleted the need to pay extra for a GDU panel with built-in SXM.
As mentioned in other comments, please remote mount the GSU 25 units. They not only don't play well with vibration mounted to the GDU screens they add complexity to the screen removal process. You will be surprised how often you will remove the GDU's to gain access to the rest of the panel during maintenance and it isn't a good idea to remove and reinstall pitot and static lines or have to unscrew the whole GSU 25 just to remove the screen.
And finally. The G5 is a fine backup. There was mention of software/manufacturer independence with respect to backups for glitch resistance. Realize that Garmin purposely had a dedicated team design and program the G5 so that there was no commonality between it's firmware and software and any other Garmin product. Meaning the G5 is every bit as independent as backup EFIS offerings from other manufacturers with the added feature of playing well with the rest of the panel via CAN Bus. In the final analysis for most flights your G5 will be a very nice fixed barometer setting knob for the whole G3X system. And having that knob is remarkably convenient I must say. Not $1200 convenient, but convenient. However, that day when the G3X goes black the balance of the G5 cost investment comes into play, which is the basic mission of a G5 in a G3X system.
Jim
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