To wrap up the interior, we finally installed all the interior panels, starting with trimming and drilling the forward interior panels:
Forward interior panel in place for drilling
Aerosport suggests 3" and 10" from the bottom for forward holes - that was almost exactly at the point where the bulkhead is, so we moved them up slightly. To get the right position of each hole, we used a similar technique to what's done for the door pins - a screw with the head cut off and sharpened to a point, to press the panel against and get markings (we used the plastic mallet to hit it a few times, which left a definite mark):
Pointy screw to mark the hole position for interior panel attachment
Doing all that underneath the panel is always fun, of course:
Panel yoga to get the interior panels to fit correctly
Forward interior panel installed in place
I installed the mid-cabin side covers and the passenger side covers - at which point I realized I left no room for the door sensor wires, so I opened up a hole and let it through with a grommet:
Passenger side panel with no room for door sensor wire to go through
Hole for door sensor wires to go through
Passenger side panel with door sensor wires going through hole with a grommet
We installed the stick bottom cover (which prevents anything from getting into the bottom area below the front seats - Vans SL-00060):
Stick bottom cover with velcro attached to it
Stick bottom cover installed in place
We also installed the mid-cabin side panels, passenger side panels, and the flap torque tube covers (all before installing the seats, but forgot to take intermediate pictures):
Mid-cabin side panels and passenger side panels installed in place
Flap torque tube covers installed
Installing the Aerosport vents required some trimming of the 3D printed duct that goes between the cover and the outside skin, to clear the cabin cover screws (unlike what the Aerosport manual shows, we did not need to tim the inside wall):
Trimmed Aerosport vent duct
With this, the only thing left in section 35 is the baggage interior panel, which I'll install after the O2 cylinder is in place.
The oil door was a bit too flexible and just latching it was making the corners rise even though it sat flat otherwise - so after adding the core, we added a layer of carbon fiber to stiffen it, instead of fiberglass:
Oil door with foam core and carbon fiber layer
Oil door with carbon fiber layer, seen from the outside
That still needs finishing to be done later.
It was then time to secure the cowl sides (that connect the top and bottom cowls together):
Bottom cowl with Skybolt flanges and receptacles installed
With all that in place, I installed the last remaining firewall Skybolts, still using the cleco adapters to center the holes:
Remaining Skybolt firewall holes, with cleco adapters for centering
Top and bottom cowl attached together, and with the last firewall holes open
Remaining firewall Skybolt flanges and receptacles riveted in place
Next is the Showplanes nose gear fairing and attaching screws to the forward end of the cowl.
I started the oil door, by trimming it and attaching the hidden hinge:
Oil door trimmed and sitting in place
Oil door with hidden hinge clecoed to it
I then made holes for the KM-610 latches, carefully setting their position forward and aft near the edges of the top cowl oil door edge:
Oil door with the latches clecoed in place
Oil door latch being actuated
Oil door clecoed in place with the latches
Oil door clecoed in place, open with the latches
When closing the door, the latches are strong enough that they'd end up eating up the fiberglass at the edge of the opening, so I used 0.020" stainless steel to protect it (folded it up around a 0.064" piece of aluminum, forming an edge grommet of kinds):
Stainless steel edge grommets
Oil door edge grommets in place
I trimmed the foam core to cover the open parts of the oil door:
Oil door with foam core sitting in place
It was then time to trim the sides of the cowl halves to make the split line:
Aft end of the bottom/top cowl split line
Forward end of the bottom/top cowl split line
With the split line sanded down to where the halves meet nicely, I installed side Skybolts.
I marked the firewall Skybolt position on the top cowl (which was about 7/8" from the edge of the skin), left 3" to the first side Skybolt hole, then 3.5" for every subsequent Skybolt flange (vertical lines in the picture below). I then marked the Skybolt flanges with lines at 5/16" and 5/8" from their bottom edge, aligned the top line to the edge of the bottom cowl while centering the larger hole with the vertical lines, and marked the tips of the bottom line along the bottom cowl. I roughly connected all of those into a single line (they never line up exactly, but they were close enough), and then marked 1" intervals along that line as the hole locations, starting from where I estimated the first flange hole to be. I realized that wth 1" spacing, if you start at about 1/8" from the side edge of the first flange, you'll get a repeating pattern every 2 flanges, and all holes end up in good locations (not too close to the edges and not on the flange's flange (the bend). I then drilled a couple of those holes, and adjusted the rivet spacer to drill all the others 3/32", then clamped the flanges (at that point you can see the bottom flange line through the holes for alignment) and match-drilled into them:
Rivet spacer in place to drill the Skybolt flange attachment holes
Bottom cowl with Skybolt flanges clecoed to it
The flanges kept pushing the top cowl outboard, to the point that even with the Skybolts, the surface of the top cowl would end up a bit proud of the bottom cowl - so we added a slight bend to the flanges to follow the contour of the top cowl (being careful not to bend the prt where the Skybolt receptacle is attached), and with that we managed to open up all the Skybolt holes:
Skybolt flange with a slight bend
Top cowl with drilled Skybolt holes
I also started working on the nose gear fairing, but that'll be continued later:
Aft nose gear fairing clamped in place
Next we need to lay up fiber on the oil door, prime and rivet the Skybolt flanges, and get the rest of the nose gear fairing in place.
I started securing the bottom cowl, first by laying out and drilling most of the Skybolt brackets (except the top ones near the split line, since we haven't cut the split yet), then match-drilling the center holes:
Bottom cowl Skybolt brackets clecoed in place
Bottom cowl right side held only by clecos through the Skybolt brackets
Bottom cowl left side held only by clecos through the Skybolt brackets
Skybolt bottom cowl brackets and cleco adapters in place
The brackets near the engine mounts required some special attention, and one of them needed to be trimmed off to not touch the mount:
Skybolt brackets very close to the engine mount
I then started attaching the actual Skybolt receptacles/grommets/retainers/studs - starting with the single ones on the bottom of the cowl, then the one in the curve, then the remaining ones - that ensured that it'd all fit tightly with no misalignment:
First bottom cowl Skybolt, at the bottom of the cowl
Bottom cowl side Skybolt holes drilled to size
Bottom Skybolts installed
The tip that helped the most for drilling the Skybolt holes was to use their cleco adapters as centering sights, and "walking" the hole to center them if needed. Unfortunately attaching these in place with both cowl halves in place is very annoying, but with a creeper and some flexibility I managed almost all of them without removing the top cowl:
Skybolt cleco adapter showing the center of the bracket hole
The bottom cowl hangs by the Skybolts alone:
Bottom cowl supported only by the Skybolts
Top and bottom cowls, supported by the Skybolts
With this, the next steps in the cowl are to trim the sides to the split line, install the side Skybolts, and install the Showplanes nose gear fairing.
I terminated the O2 regulator wiring - I saw no reason to use the MH-provided extension dongle, since that'd just add another intermediate connector which seemed unnecessary:
I secured that to the baggage area floor, and secured some of the remaining wiring like fuel level wires and the stick grip wires:
Fuel level wire secured to avoid the rivet line
Stick grip wires secured to the landing gear mount
It was then time to continue the firewall-forward wiring, and deal with those annoying Adel clamps:
Left-side spark plug and other sensor wires secured to engine mount with Adel clamps
Spark plug wire organization near the coils
Right-side spark plug wires secured to the engine mount
For the bottom wires, I used the Vans C-606 tabs so that I can install and remove the Adel clamps without having to unbutton the sump every time:
Alternator wires secured to the engine sump
I secured the crank trigger sensor wiring to the top of the engine case, using one tab and attaching the second Adel clamp to the existing bracket:
Next I need to finish the cylinder wiring brackets, and finish routing the crank trigger wiring aft through the rear baffle.
