09: Fuselage – N2469Z

In this section, my focus moves to the main fuselage, starting with building up the floor section.

First, I need to create some framing pieces that will later get attached in to the floor’s structure:

Double flush rivet, then smooth down with the soft deburring wheel, then primed that area where the alclad was broken.

Here we have the beginnings of the spar box

With all those pieces prepped, it was time to do some priming

Now it’s time to prep some more parts for primer

Now to start assembling some things

Caught up the other side with the hearing plate and got the nut plates installed

Crotch strap assemblies riveted together and nutplated

These bearing blocks become the pitch axis of the control sticks later in the build..

With those ready, it was now time to start dimpling the bottom skin of the fuselage

Need to be careful when back riveting. Sigh.

With that dimpled and some doublers added, the process of attaching pieces to that base skin started

Upon getting this far, I discovered that a couple ribs were installed incorrectly, so I had to remove them and put them in the correct orientation (and on the correct side, left and right side were swapped for these two incorrect ribs) and then finished attaching the skin

With that done, it became time to prepare for another primer session

Unmasked; this is where the other bottom skin pieces overlap, so we prime there too per the instructions to protect this area from collecting corrosion in the future

Once this priming session was completed, it was time to start gathering parts for the next sub-assembly, which is the firewall and its supporting pieces:

With the firewall ready, next up was to get the forward floor and tunnel assembled. The tunnel supports both a “cowl flap” of sorts to help provide a path for engine compartment heat to escape if the flap is opened.

These parts were in a special bag and were forgotten during the initial primer run for this chapter, so I used the 3chem aerosol can after running them through the prekote process

From here, it was time to drill a hole in the firewall (that I later discovered I won’t use) and put its fitting on, put the cabin heat valves in (these will be important later), and secure the foreward part of the spar box. From there, I will attach the two halves of the fuselage floor together

From here, it became time to start getting some bulky bits of aluminum ready for installation. I had to countersink some stuff, twist some longerons, and secure the spar box

A surprising amount of twist required to get the desired amount of resting twist before mounting to the fuselage

With that work done, it was time to prime those and some other parts.. Including the side skins!

With all those parts primed, it was time to get that whole fuselage floor built. I started by getting them clecod and the bottom skins lapped over, and then put these pretty beefy side braces and chonky bits aluminum in over the front and aft pieces of the spar box, and that turned it in to a pretty rigid structure before even setting a single rivet. From there it was just time to start setting rivets. I 3D printed a stand that went in to the spar box so I could stand the whole assembly up on its edge, and this worked out pretty well.

These side braces added a LOT of strength to the assembly before setting the rivets, and made it feel quite secure when standing the whole thing up on its side

I built the coupling arm that the pilot and co-pilot control sticks mount to. Then, forgetting I had purchased some shim-washer holders for steps like this, I invented and 3D printed some washer holders so I could install these pieces in to the cockpit

The Michael came over to check on status while visiting from the other side of the country, so naturally I put him to work. We built these braces that are used later..

Next up was some side skin prep and making the lower cowl attachment using piano hinge stock. More of that lovely tank sealant was required in here too

I finally got Levi to come by and help for a little bit. I got him some time on the countersink tool and also some dimpling and riveting. I love getting friends’ names in to the builder’s log, I think this will be a great way to keep folks connected to the airplane and all the memories I’m able to build in it.. After he left and in the days that followed, I started getting the skins permanently attached to the floor structure, including the longerons, various stiffners and a couple aesthetic pieces. This process was very fun, and it really started to hit me that one day, this will be a cockpit that I’ll sit in and fly.

With the skins installed, I had to install these little wing root fairing attach pieces on the outside. Eventually, when the wing is installed, there will be a gap between the wing skin and the side of the fuselage so that you can do maintenance and inspections for the systems going between them. To facilitate that, you can take those root fairings off, and when you reinstall them, they’ll screw in to these pieces and just look like nice smooth wing skin all the way to the fuselage skin, nice and clean.