Some of the rivet callouts in 20-03 Fig 3 are a bit suspect. eg It suggests you machine countersink the ADAHRS retainers, which are far too thin!

I couldn’t see a good reason to use 426’s anyway, so I ended up using AN470AD4-6’s rather than the specified AN426AD4-7’s.

I clamped the assembly securely in the vice when squeezing these 1/8″ rivets.

Then I dusted off the trusty C-Frame to set the rivets which attach the W-00012E ADAHRS Mounting Zee.

I clamped the W-00009B Wing Box J-Stiffener to the bench …

… and then used the squeezer.

GMU 22 Mount

As I’ve previously mentioned, I am fitting the Garmin GMU 11 magnetometer, but since I had bought the GMU 22 mount ages ago, I decided to use it to provide a removable mount for the GMU 11.

I am going to mount the unit along the pitch axis.

In order for the mount to slide into the ADAHRS retainers, the flange 426 rivets are double flush. I countersunk the flange holes by hand due to the usual access faff!

If you have the GMU 22 kit from Vans, this bit is all explained in the supplied Section 62.

The shop heads flattened nicely into the countersinks.

But does it fit in the mount? …

… yep!

It fitted very snuggly and securely, but will be easy to slide out of the wing if required.

Here’s the plan for the GMU 11. The G3X Installation Manual says it can be mounted in any orthogonal orientation, so by mounting it like this the wires will head straight to the wing root.