Joshua’s RV-9A Project

Worked against the weather today to get the wing skins primed.  While the spray gear was set up, the baggage wall pieces were primed and painted, as well.  Thinning the Rustoleum paint has been hit-and-miss, and today’s batch was a miss…I think it was thinned out too far, and the panels ended up with very heavy coats to get the coverage needed without pinholes…they have a different look than the rest of the interior; for now, we’ll let it go, since there are other inconsistencies, and these panels can easily be pulled out, stripped, and repainted later if it becomes bothersome.

Also finished wiring the internal parts of the wings, trimming the wires to length and crimping on the connectors for the landing lights and the D-sub for the autopilot servo, and terminating the leads to the pitot heat control board.  I later realized that I have not yet run cable for the OAT sensors which will be installed in the right wing to feed the EFIS boxes.  I also epoxied some zip-tie bases to the underside of the seatback bulkhead for holding the headset jack wires, and installed the baggage light strip under there as well, using it’s built-in adhesive strip.

Neighbor Jeff stopped by to check on the progress; it’s been awhile since he’s seen the project.  People who see it now say it looks like an airplane.

A collection of things happening in the shop today.  First thing up, finish the canopy sealing.  The excess Sikaflex was rubbed off the exterior of the top skin and the inside of the rear window and canopy (from gluing the spacer gaps), followed by removal of the rear window spacers and insertion of sealant into those gaps.  Smoothed those over with tongue depressors and all looks good.  Some canopy work remains, of course, but the plexi is in place (which was the big summer goal).

Before the gear can be put on the fuselage, the wings need to be fit, which was skipped earlier in order to get the canopy done in the warmth of summer.  In order to do that , the wings will need to be finished (bottom skins riveted on, which means that they must be wired and plumbed).  Out came bottom wing skins, which needed edge deburring and a few dimples made.  After those were done, the skins were etched for priming along with the rear baggage wall; unfortunately it was too windy to prime until after dark, so that’ll have to wait for another day.

Cleaned up the inside of the wings, which had naturally collected a layer of shop dust and spiderwebs, and set about running the various wires and tubes for the in-wing systems (pitot heat, lights, strobes, AOA, and autopilot).  Everything except the pitot tube was run inside the corrugated conduit which was installed during the wing build.  A hole was drilled in the conduit near the aileron bellcranks, to permit wires to emerge for autopilot and pitot heat; once these wires are in position, some RTV can be used there to prevent any chafing on the conduit edge.  The control module for the heated pitot was installed on the rib near the bellcrank inspection hole, which should allow access to hook up the pitot wires later on.  The pitot tube was secured underneath the aileron bellcrank with an adel clamp to prevent interference or chafing.  All the wiring and tube will terminate at the wing root in connectors, to allow the wings and fuselage to be fully wired in the shop, and easily joined at the airport later on.

Before leaving for a day with the girls, Allison helped drive the remaining rivets on the right wing.  All went smoothly, and we finished the main spar and J-stiffener in around an hour.

In a morning and an afternoon session, Allison helped rivet the second pass on the top skin ribs.  After that was done, I slid the J-channels in place and clecoed them to the skins.  I also squeezed the rear spar-skin rivets, so all that remains on the top skins are the skin-spar rivets and the J-channels.

Also picked up lumber and a sheet of 3/4″ MDF to build a box for flap & aileron construction.

This morning, spent a couple hours at the quarterly meeting of the Twin Cities RV Builders’ Group, chatting about planes and listening to stories.  Had the chance to visit Mike Behnke’s recently flying -9A and sit in the copilot seat.  A well done airplane.  Really liking his panel; even better in person than in pictures.  Playing with my paper cutouts, I figured that two AFS screens (my long-term plan) should be configured one on the pilot side, and one on the copilot side, with the radio stack in the middle.  Sitting in Mike’s cockpit (where both screens are in front of the pilot), I had no problem seeing both screens from the right seat–and since the displays share data and any screen can appear on any display, the right-hand display could be configured as the flight data screen if the copilot is flying.  He also still has room on the far right of the panel for a third display; I think an AFS 3400 would fit there, or a Dynon of some variety for dissimilar backup.  His panel is ~1 1/4″ longer than stock, but legroom didn’t seem to be an issue (I was able to sit with my knees bent up), and I think it might be possible to tighten things up a bit more, if a person was concerned about the panel length.

In the evening, Allison helped rivet the rest of the first pass on the top skin rivets.  After that, we fixed the few rivets that needed drilling out, and I pulled clecoes in preparation for the next session.  Also drilled out the rivets on the left wing that I squeezed into the holes intended for the root fairing screws…a stupid oversight of plans-reading on my behalf.  All those holes have also been dimpled, so I’ll be reading ahead in the manual to see whether that’s a problem, or if I need to flatten them out.

Allison helped rivet the first pass on half the top skin to rib lines.

Dusted off the right wing skeleton and dropped the fuel tank in place.  It clicked right into the dimples and lined up nicely–all the bolts for the Z-brackets lined right up, save for the inboard-most bracket, which needed a little finagling (as it did on the left wing).  Inserted & torqued all the spar-tank bolts, then all the screws.  Used a new screwdriver bit, and only managed to mangle two screw heads…gotta get one of those “grippy” bits with the tiny serrations on the tip, maybe those hold on better.

Followed up by clecoing on the top skins, interpolated with plenty of wing-twist measurement checking.  All’s good…ready to rivet!

Primed the top skins, wing walk doubler, and J-channels for the right wing, along with the retainer brackets for the landing light lenses.  Discovered that small bugs are attracted to the large, freshly primed skin panels as the light dims in the late evening–probably because they’re rather white.

Summer is the time for working on projects…and this summer, that’s meant remodeling the bathroom more than building an airplane.  I’ve spent the last three weeks on that project, with at least a week to go, taking into account the fact that I need to go to “real” work at least occasionally…  A complete strip-to-the-studs and buildout of our small bathroom, to follow on the (unplanned) porch and patio projects from last summer.

Not to say there’s been no work on the plane…I set Allison to work deburring and dimpling wing skins when she complained of being too bored.  Several nights ago, I reconfigured the shop for riveting the right wing, plumbed and leveled the skeleton.  Tonight, I did primer prep on the top skins and J-channels for the right wing; hoping to get a chance to prime them tomorrow after work.  I’m guessing we’ve found 6 hours or so in the last month.

Time flies, even if I don’t; school will be starting again before we know it.

Allison was bored enough today while I was at work that she dimpled most of the holes in the right wing top skins.  I also spent some time fiddling with the Gretz pitot mount when I came home…looks like it should be relatively easy to fit up.  Need to read up on the best location (inboard or outboard of the bellcrank bay?) to install it.