Joshua's RV-9A Project

With the towing company on the schedule for tomorrow morning, I wanted to see how many of the little things left on the pre-airport punch list I could get done.  A pretty successful, if short, session, I think…

Riveted and installed the lower cowl support bracket that was fabricated on the weekend.

Torqued and safety-wired the propeller.  Temporarily reinstalled spinner with three screws (this won’t be final installed until the engine is ready to be run; inspectors will want to see the prop bolts.)

Re-checked the alternator belt tension, which is fine with a breakout force of around 130-140 in/lb on the beam torque wrench.  (The desired spec is 11-12 ft/lb, aka 132-144 in/lb).

Tightened up the nosewheel axle bolt temporarily; we’ll revisit all the gear hardware at the airport again.

Cut the temporary zipties off the gear legs, and replaced them with new ones after placing a wrap of orange silicone fusion tape around the leg under each tie location.

Cleaned up a wavy spot in the aft edge of the canopy on the RH side, straightening it out along a marked tape line.  This gives an even gap ~1/8″+ all the way around the canopy split, which should be wide enough to prevent expansion in the heat causing the canopy to stick shut, based on what I’ve read.

Swept the shop, moved some things around, and pulled the plane in front of the garage door, so it’s ready to roll out tomorrow.  Taped down things that could rattle in the wind while moving.  Vacuumed the various debris out of the cabin.  Took a fistful of photos.

After 1751.5 shop hours, ~5.5 years after project start, she’s going to the hangar.

Attended the quarterly gathering of the MN RV Builder’s Group this morning; saw the new -9 under construction by a repeat builder, including a nice panel being built with triple-screen G3X and GTN650.  After scoping out the plane and downing some danishes, I was able to corner Tom Berge, who does nosewheel transition training locally.  Picked up the info I needed to plan for transition training, and Tom also said he would be willing to conduct the first flight.  He recommended I get in touch to start transition training when I’m about a month from first flight, and after getting current again.

With that sorted out, back home and time to finish the plane…  First thing, as usual, was to sand down the layers which were applied yesterday.  With that, I was able to finish shaping the nose, straighten up the oil door cutout, smooth the side hinge lines, and get the top skin/canopy “air scoop” fixes to the right shape.

The entire plane–and builder–being now covered in fiberglass dust, and given the lovely weather outside, I decided to roll the fuselage into the driveway and wash it.  That went well, and I quickly found out where the leaks were.  As I was rinsing it off, a local couple we know who had been out on their bikes rode up to check it out; Ben is a retired airline pilot and interested in the project, so we looked & chatted about that, as well as the various animals that have taken over the yard.

After drying (microfiber is amazing) and wiping up after the leaks, it was back into the shop for more work.  Displaced the canopy for access and filed the aft edge of the canopy joint micro back to where it ought to be, then filled all the gaps between the skin and the weatherstrip seal with Proseal.  Once set, I’ll trim any goobers and it should provide a much higher level of water/dust ingress protection.  During this process, neighbor Jeff stopped by to check on the progress, having seen the plane in the driveway earlier, so chatted for awhile about various things.

Final task for the evening was to spread a coat of epoxy on the interior surface of both cowls.  This will be left as-is, to provide a solid shell which will protect the fiberglass against oil and other fluids and ease cleanup of drips.  The interior of the cowls will be painted white to lighten up the engine compartment for preflight inspection, and make any leaks easier to spot.  Also added some micro to fill divots in the canopy joint filler.

Milestone: rolled over 1700 hours on the project today.

Spent most of the day today doing cowling-related things.  This weekend might see the transition from shaping work to finishing work (finally). Started with more sanding of stuff that had been applied previously: the nose ring and outboard corners.  They’re looking decent; one more layer of micro applied to fill holes and divots.  As long as I was mixing up micro, I put some along the side hinge lines to smooth those transitions, as well as around the oil door, after wrapping it in tape.  Later, after the micro had hardened but not fully cured, I was able to shave off the excess and pop the oil door out.

Also dealt with the side hinge pins: bent a 90* angle in the front, and another bend to allow the pin to come out from the slot.  Wrapped it around a #8 screw to make a ring to secure it.  Seems to have come out OK, and it’s in the spirit of the Van’s hinge eyelet, but a little more elegant.  Not nearly as pretty as the recessed coverplates, etc that are often showcased, but it’ll fly…I can make a fancy coverplate and fill the screw hole before paint, if I want.  Riveted a nutplate to each side of the cowl with an aluminum backing plate for reinforcement.

A similar thing was done to the inner side of the air intakes where the cowls overlap — drilled for #8 screw, installed nutplates with an aluminum doubler.  Upper cowl countersunk for tinnerman washers.

Perhaps against my better judgement, decided to bite the bullet and add a “ramp” of micro to the top skin ahead of the canopy, to cover up the “air scoops” on the canopy to fwd skin joint.  That means I’ll have to spray primer on this, because it’s pretty ugly now with the sanded skin and white micro filler.

Also printed & installed placards for tank capacity at the fuel selector, and installed the dataplate which has come back from the engravers along with the fuel caps.

Sanded and shaped the micro filler added to the cowl in the last session.  Refit the cowl to the plane and made up a “tool” to sand the nose to a consistent gap behind the spinner: a piece of plywood drilled with the prop hole pattern, and some cardboard shims to adjust the spacing.  By bolting this up in place of the prop/spinner, I could set the space between the plywood and the cowl nose.  Adjusting the spacers so that my sanding block (long piece of 1×3 with abrasive glued to one side) would slip between the board and the cowl, and sanding until it moved freely, worked quite well.  It turned out that a couple areas of the nose needed more filler, so the cowl was removed again and more micro applied.  More sanding to ensue on the weekend…

Decided to quit reinventing the canopy seal wheel, at least for now (since they’re easy to keep fussing with over the long term)…located & installed the factory canopy seals.  The white P-profile foam one in the front, which looks like it will work, and the teardrop-profile one at the canopy bow.  This one is made of a more slippery rubber, rather than the foam of the one I had tried earlier; that fact allows the canopy to close with much greater ease–the foam rubber one was “grippy” on the plexi as it closed.  I installed this with taller part of the teardrop facing forward, so a valley is formed between the seal and the rear window plexi; the hope being that this will provide a channel to direct any water that enters the gap down to the sides.

More work on the list:

• Installed metal locknuts on the baffle tension rods.
• Torqued & marked the “squeeze bolt” on the fuel servo-airbox ring.
• Cleaned the airbox, fully assembled with bolts.  Torqued & marked all the airbox bolts.
• With the canopy seal sorted for now, reinstalled the EFIS and tested.

Another warm day (but this time breezy and hazy as well).  Trying to cross things off the list…

First on the agenda: loaded up the empennage and moved it to the hangar, where it will wait with the wings until final assembly.

Next, set up the day’s fiberglass job.  Added a couple plies to the nose flange layup from yesterday, to give it more stiffness.  Closed off the inboard ends of the cooling inlet ramps with a 2-ply layup.  Added flox to a couple spots and deep voids.  Again today, I meant to get two rounds done, so one could cure overnight, but ran out of day.

Spent awhile fussing with canopy seals.  The edge-gripper bulb seal I wanted to use on the front seems a bit too thick, as it’s interfering with the closing of the canopy — the latch requires immense force to actuate.  So, that was removed for now.  I added the same bulb seal to the side rails, and that also cause latch trouble, so I ended up slicing the bulb in half for about 60% of the length of the side rails.  It looks ragged when open, but seals fine when closed.  This is easy to replace later — I’m searching for a smaller bulb, but the 3/8″ is the smallest I’ve found so far.  I may have to explore using foam strips or something.  Also ran into trouble with the rear rollbar seal, again, difficult to close & latch.  Will explore more seals; it seems this is a spot everyone struggles to make work.

On to the “little stuff:”

• Slipped some clear tubing over a couple fluid lines in the tunnel to prevent any possible chafing from wire bundles (clearance is fine, but vibration does things…)
• Installed the fuel selector & torqued all the fluid fittings in the center tunnel.
• Installed the fuel pump and torqued those fittings.
• Installed the metal plug in the hole that provides access to the nose leg bolt.  Sealed up with a good layer of firewall sealant on both sides.
• Installed the bolts on the RH lap belt, having received my order of hardware from Spruce.
• Finished off the firewall wiring passthrus per instructions, since wiring is complete.
• Torqued the forward bearing on the aft elevator pushrod.
• Checked that all bolts on the flight controls were torqued, and torqued them where they were not.
• Swept the shop and put away tools, brake bleeding stuff, and so on.

Indeed the sun is shining, the weather is record-setting unseasonable warmth (avg. high today of 51, we hit 79 here, and over 80 at the airport; at 23:30 local, it’s still 65).  Perfect fiberglassing weather, so that’s how I started the day.  Sanded some spots on the inside of the cowling, and laid up a couple plies of reinforcement when the nose-shaping operation had caused it to become a bit too thin.  Also laid up a new flange on the right bottom nose to replace the one that I cut off during fitting.  Added some micro to the leftover epoxy and filled some divots in the surface, along with putting a layer over the vertical hinge rivets on the aft edges.  Should have put one more batch before ending the night, but ran out of time.

Took another crack at re-bleeding the right brake to remove the air in the line (which causes “squishy pedal”), and got it this time.  Left & right pedal feel is equal now, both quite firm.

Decided that in the pursuit of progress, and given the generally-finished status of the avionics, wiring, and plumbing, it was time to nail on the forward top skin.  Sealed the forward edge with firewall sealant; I was able to set all but the longeron row + 4 rivets myself.  When Allison came home I conned her into shooting those remaining, while I laid upside down in the cabin to buck.  After that was done–as long as I was down there–I installed the top canopy hinge bolts, and the canopy pin mechanism.  During the solo riveting of the skin, I also secured the standby alternator relay & capacitor (which needed to move out of the way to allow bucking access).  Once the riveting was done from inside, I squeezed the rivets along the firewall, which also fasten the camloc strips.  With those in, I installed the three remaining camlocs.

It seemed natural to move next to the canopy, so I trimmed back the seal flange on the subpanel by 1/8″, to allow for an “edge gripper” type seal to be affixed.  We then installed the canopy on the fuselage, with much consternation around getting the hinges aligned with the pins (as the alignment marks I made earlier had been removed from the hinges during some cleanup).  Reaffixed the lift struts, and checked opening & closing operation, which worked fine.  The riveting of the top skin, as it seems to often do, changed the fit of things and created some “air scoops” on the pilot side, though the copilot side looks decent — both sides were alright before riveting.  So, I’ll have to decide whether to drill rivets & try to shim it up, or build that side up with (more) glasswork now, or later.  Since the canopy stops were removed to gain access for riveting the top skin, I reinstalled those, though they still need a little adjustment before locking them down.

Put in the pilot seat temporarily to sit in the plane and check fit & function of the lap belts, and operation of the canopy, brakes, and panel floodlights.

Finished the canopy skirts by stripping off the excess Sikaflex that oozed out of the joint and riveting the skirts in place.  All rivets were easily squeezed except five, which were bucked.  One of the nice things about Sikaflex versus something like Proseal is that, while it sticks with vigor to any properly primed surface, it doesn’t stick to things not coated with Sika primer; so it’s easy to not worry about the ooze-out, and once it has cured, just scrape or rub it off.  Cleaned all the dust off the canopy frame & underside.

Pulled out the prop and various related pieces — spinner, bulkheads, spacer, crush plate — and set to work making the blade cutouts in the spinner.  Measuring, making cardboard templates, and cutting, then shaping with a file, followed by lots of iterative fitting and filing, was the order of the day.  Got it to the point where it fits, though the cutouts will need to be cleaned up for a consistent gap width.

Mixed up some Super-Fil and worked it into the remaining pinholes on all the fiberglass parts that were sprayed yesterday.  Next will be sand the filler & spray another coat.

Pulled the top skin off and moved a couple pins on the ADS-B connector, since newer versions of the box have a slightly different pinout.

With the top skin off, found that a few of the elbow fittings on the brake cylinders were leaking fluid.  Removed the hoses and turned them in one more rotation, which, at least initially, seems to have cleared up the slight leaks.  Re-bled the brake system with fluid, and in the process managed to snap the nipple off one of the bleeder screws.  Dangit — at least it was only the nipple, so the brake system is closed, and I just need to order another bleeder screw.

Reconnected the oil temp sensor wire, which had been removed in a previous session to install an oil line.

Hooked up the new serial converter and it works; checked communication with the Pmags, and verified the configuration in the APRS tracker.

Finally, a work session with something more than sanding.  Worked a bunch of list items over a full day in the shop:

Brushed epoxy on the front of the top rudder tip, filling the pinholes in the micro which was sanded yesterday.  Added a blob of micro to the trailing edge, where the glass tip ended short of the metal portion.  I’ll refit this to the rudder tomorrow and sand the tip TE to match the rudder.

Set up a plastic-sheet spray booth, cleaned the HVLP gun,  and sprayed PPG DPLF epoxy primer on the canopy fairing, HS and VS tips, elevator tips, rudder bottom, and empennage fairing.  After that, it was time to air out the shop and bring it up to temperature again, as the epoxy primer and subsequent gun cleaning step kick off a lot of fumes.  I found only two pinholes in the canopy fairing, both over screw heads.  The emp fairing has a goodly number still (as I expected), and the tips have a few.  I’ll let the primer cure overnight, then fill the holes and sand level before laying down the K36 which is the next step in finishing.  That puts the second coat on schedule for Monday or Tuesday, though it looks like I may have to work on Tue night.  The recoat window is one week.

On to the cowling, I cleaned up the cut line on the rear of the inlet duct, then fabricated a piece of airseal and a metal backing strip, fitting them around the bottom of the duct.  This will mate up with the top piece, which is installed on the airbox, to seal the gap between duct and airbox.  A test fit, after tweaking the alignment of the airbox, showed it worked well.

Next, I countersunk all the rivet holes for the cowling hinges, and drilled some “ooze holes” in the hinge to give epoxy something extra to bond to.  Sanded the cowling and the hinges with a rough grit, and laid a bead of epoxy/flox along the hinge lines.  Clecoed the hinges on, then riveted them down, and cleaned up the flox that squeezed out all around.  Ran hinge pins through the hinges to make sure none of the eyes were epoxied shut.  Also floxed/riveted the oil door hinge to the cowl and door.

Put rivets in the remaining 5 holes under the left side canopy deck, originally left open to attach clips to hold the static line.  One hole was behind the center section cover, and inaccessible for bucking, so I used a Cherry rivet instead.

Torqued the nuts on the control cables at the quadrant, and the stopnuts on the control horns attaching the cables to the quadrant levers.  Verified that cotter pins were installed on the horns (they were).

More sanding, and nothing but sanding.  Sanded down the coats of epoxy that were applied to the canopy fairing last night; I think it’s going to come out alright.  Masked off the canopy and Allison helped me move it to sawhorses to wait for spraying.

Sanded down the empennage fairing, so that can be primed too, though there are a couple spots that need a bit of micro and followup sanding.

Spent the rest of the session starting work on the emp tips: final-drilling the holes, dimpling/countersinking, and sanding for primer.  One of the elevator tips needs a little micro along the seam, and the rudder top fairing will, too.  Hoping to get the rest of the tip work (just the rudder bottom) done tomorrow and apply some micro, then spray all this stuff midweek.  I think it’ll be a mental boost to have all the glasswork except the cowling “done” (for now, and excepting gear fairings which will probably wait until after first flight.)