Front Cabin Assembly

While I’m waiting for the replacement engine mount attach bracket I proceeded with initial assembly of the forward fuselage.

I’m finding it helpful now to assemble a bit beyond each of the riveting sections in the plans as it helps me think a bit further ahead.

This section starts with the bottom skin and the ribs that are under the front seat foot wells.

I upsized the hole for the brake line fittings to 5/8″.

I then separated and cleaned up the systems brackets. I’m leaning towards an electronic ignition system (SDS) which means I’ll need a return fuel line so I’ll have to make some modifications here.

The firewall assembly isn’t fully riveted yet but I went ahead and clecoed it into place for any match drilling that was needed. All of the rivet holes were already final sized between all of these parts which was a huge time saver!

The flange below was then shaped to fit the gear leg mount.

I then clecoed the forward bulkhead into place and match drilled the AN3 bolt holes.

I then decided to test fit the gear mounts. The bottom holes need some enlarging so I decided to do that now instead of later when everything is riveted into place.

The outside of the hole has a very thin connection point which got so thin that it separated. This all resides inside a fairing so I assume I can just round off those sharp points.

The plans have you attach the brake line fitting to the gear mount later. At that point the gear mount will be bolted into place and there will be no way to get the fitting to seat against the gear mount as the flange on the fitting won’t fit through the 5/8″ hole in the skin. The hole in the gear mount is also not big enough for the fitting and will need to be upsized. I’ll probably check in with Van’s to be sure but my plan at the moment is to upsize the gear leg hole and then upsize the skin hole to allow the bracket flange to pass through. It should be much easier to do this now than later while crawling under the plane.

Edit: The above info is incorrect.. I had been looking at an AD-6 elbow, not an AD-4 (oops, wrong bag of parts). Thankfully I caught this while triple checking before upsizing the hole in the gear leg mount.

The hole in the gear mount also doesn’t line up perfectly with the skin hole so I’ll probably widen the skin hole with a Dremel to move it in the right direction.

Starting to see the forward cabin coming together.