Joshua's RV-9A Project

Long week at the various jobs, and we’re now into the busy season–job work every weekend, so project work will drop off rapidly until mid-June.

Sanded micro filler on the top skin.  Applied SuperFil to pinholes there, and on the cowlings.

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.

The “before airport” items on the punch list now fit onto a single printed page, so we must be getting closer, right?

I’m pushing to get the cowling to a point where I can start doing finishing work on it, rather than shaping work.  I think when we get to the point of spraying the cowl, it will be a major milestone, and the light at the end will feel much brighter.

Spent several hours sanding the cowling today — smoothing edges of the cooling ramp layups, truing edges, aligning things, sanding down filler, and initial shaping of the micro blobs on the outboard nose sides, to make the top & bottom even.

Added another inch to the gear leg slot, which should provide just enough clearance from the prop to get the thing on & off without dinging either it or the prop (after protecting the prop blades with something).

When all the sanding was done, took the halves outside and sprayed them down with the hose to remove all the dust, then dried them inside.  Applied another batch of micro to the nose ring, filling the spots where the gap was wider than desired.  This will be sanded back to provide a consistent even gap all around, and will probably take another layer or two of micro to finish off.

Drilled the gap filler pieces for nutplates, and countersunk those 3 holes in the spinner.  Primed and riveted the spinner bulkheads, gap fillers, and gap filler flanges.  At this point, the spinner is ready for fiberglass finishing.

Installed the radios into the avionics stack.  All that remains to reinstall is the EFIS, which I’ve left out for now while I continue to ponder canopy seals.

Pulled the dessicant plugs from the engine to bake, as they were beginning to turn color.

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.

Trying to finish up the spinner/prop install.  Re-fit the spinner to the bulkheads, measured marked and drilled the holes which attach to the forward bulkhead — forgot what I was doing and made a 9-hole pattern instead of the prescribed six.  It’s good and sturdy now.  Final drilled all the spinner-bulkhead holes for #8 screws, and countersunk for tinnerman washers.  Removed the assembly from the plane and drilled/deburred/countersunk and riveted the 24 nutplates.

Screwed the spinner to the aft bulkhead on the bench, made a rough template for the gap fillers, then marked and cut three of them from .063.  Fit the plates to the holes and drilled for 4 rivets each per plans.  Then, reinstalled the bulkheads, prop, and spinner, and made another rough template to trim the gap fillers to the contour of the prop.  One at a time, mark/shape/file/refit/repeat to get the gaps and contour correct for each blade position.  (They’re not all identical due to variations in the spinner’s blade cutouts.)  As the day’s final task, cut and bend three tabs out of .063 stock, which will later be affixed to the back of each gap filler, and drilled to the spinner to provide a place to secure the filler to the fiberglass with a screw.

Had hoped to get a start on some of the cowling glasswork today, but duty called.  I’m trying to take 3 more days from work over the next two weeks to knock some of this out, but it’s getting to the busy season and many evenings are lost to one workplace or another.  It may yet be feasible to fly before summer, but it’s looking more doubtful each passing day.

Several list items in this weekend’s work session.

Having received the 1/4″ threaded drill I needed, drilled & deburred the crotch strap mounting holes.  Installed the crotch straps.  Drilled 1/4″ attach holes in the lap and shoulder belt attach points, and mounted those (RH lap belt temporary, as I ran out of the correct length AN4 bolts).

Final-installed the baffle screws with lockwashers.  Replaced temporary nuts with metal locknuts on baffle mounting brackets.  Fabricated and temporary-installed the baffle tension rods (need #6 metal locknuts), with nylon tube over the middle parts; they don’t contact anything as is, but should something shift, the nylon will prevent wear until the next inspection/oil change/etc.

Applied packing tape to the forward spinner bulkhead, laid a bead of flox on the inside of the spinner at the contact point, and clecoed it in place.  There was a moment of concern when the spinner didn’t want to release from the tape after curing for a few hours–I wanted to let the flox set up to hold proper shape before removing the spinner.  After pushing, prodding, tapping, and finally whacking it on an angle (it took quite a few good double-fisted whacks…that’s a strong piece of fiberglass…), one section popped loose and I was able to work it free.  Trimmed the squeezed-out flox off with a knife, to save weight and keep the spinner as balanced as possible, since this is part of the rotating mass.

More work on fitting the spinner; finished the blade cutouts to an even 3/32″ width from the blade.  Set up a ladder to hold a fine-point sharpie while rotating the prop & spinner to ensure that the spinner was centered, then marked a line around the circumference at the rear bulkhead.  Using tape and a rivet fan, spaced 5 holes between each prop blade and drilled  #40.  These will later be enlarged to final size.  Clecoed the spinner in place and checked centering again, before removing and installing the forward spinner bulkhead.  This also requires trimming to clear the blades, and final-sizing the bolt holes to the required 7/16.”  The initial fitting of the spinner is done; the next step will be to add a bead of flox around the inside at the station of the forward bulkhead, to take up any remaining gap and minimize screw stress & vibration.

Cut the nosegear log slot 3″ longer in the lower cowl, to make it possible to clear the 3-blade prop.  I may extend it another inch still.

Sanded down the micro that I’d applied to the voids in the lower cowl nose, and marked lines on the top cowl where I’ll lay up some glass to close the inboard ends of the inlet ramps, to prevent cooling air from being dumped to the lower cowl without doing any cooling work.

No work for the next couple nights due to other commitments…