G3X Gotcha - GSU 25

[phapp]

It may have been said before, but I cannot stress enough:

"YOU MUST WORK FROM THE MOST CURRENT G3X DOCS!"

Here's my example to help the next person.

I laid out and ordered my pitot / static supplies from Stein. But I was working from my GSU 25 info out of a previous version of the install manual.

The problem? I thought I remembered the docs saying unused ports (the AOA) should be plugged with a proper plug and not the red plastic plugs supplied.

As I went to finalize the installation I refer to the most current install manual ( REV AJ) find that the AOA port should be connected to the static line. In addition, they spec a star washer for the mounting.

For me, using a manifold, I need to make some design changes to add that static line to the AOA port. As far as the star washers, there must be a reason they added them. I have a collection, so not an issue.

Talk about minutia, but these attentions to detail are what prevent the squawks BEFORE they raise their ugly heads.

In a perfect world we would build our airplanes faster and Garmin would have a mailing list to inform of us every doc change. But it's all on us to step up.

Fortunately I have that "retentive" nature that works so well for aviation endeavors.
To paraphrase JFK regarding the moon shot, "We choose do these things because they are hard. Not because they are easy"

[JDA_BTR]

You might find it easier to just cut the static line and install a push connector T. The AOA line can just stub into the T no fuss. But I’m surprised that it is desirable to connect the aoa to the static. That seems sure to cause a change in static pressure readings? If you cap off the Aoa what difference could that make except it could collect water and ice up in some situations? I hope someone explains the why and all of this.

[Brantel]

Originally Posted by JDA_BTR

You might find it easier to just cut the static line and install a push connector T. The AOA line can just stub into the T no fuss. But I?m surprised that it is desirable to connect the aoa to the static. That seems sure to cause a change in static pressure readings? If you cap off the Aoa what difference could that make.

You only connect the AOA port to the static if you don't have an AOA probe connected.

This is to protect the sensors inside the AHRS from damage during static system checks. Too much differential pressure on those ports can cause sensor damage.

[JDA_BTR]

Yep I wasn’t thinking about that end makes a lot more sense.

Aren’t those fittings NPT threaded? How does a star washer help?

[Brantel]

Originally Posted by JDA_BTR

Yep I wasn?t thinking about that end makes a lot more sense.

Aren?t those fittings NPT threaded? How does a star washer help?

I think he was referring to the mounting hardware.

[tjyak50]

We are about halfway through my G3x install when AJ came out, I had originally printed AG.

Some substantive changes.
My installer also references his other manuals for Certified applications of the same device and those often have more detail it seems.

Probably minutia, but might as well nail it as best possible.

T