Joshua's RV-9A Project

Began the day with some excitement; nearby -9A (and now -10) builder Mike Behnke was gracious enough to bring his plane down to Red Wing this morning so I could have my first RV flight — a great one!  The day was warm, calm, and relatively clear, and Mike’s plane looks and flies great.  My only experience being in 150/152/172 types, the stick-and-pushrod controls were a new thing, and a joy to fly; no slop in the control system, and just a bit of pressure required for control.  We did some turns, stalls, a bit of sightseeing, and Mike demonstrated an autopilot-coupled GPS approach.  Also got to see the AFS screens in flight, as his panel is practically identical to mine (both equipment and layout).  We also chatted about fiberglass, transition training, inspections, first flights, and so on.  Many thanks to Mike for the opportunity!  It’s another inspiration to work through the endgame of my project.

On my way out of the airport, I stopped by the hangar and pulled the fuel caps from the wings (and taped over the filler holes), as I’m considering sending them in to be engraved with the required markings, rather than using a sticker.

Into the shop after lunch, I spent several hours sanding the micro filler on the canopy fairing.  It turned out pretty well, and I think I’m going to try and move ahead with it.  To that end, I squeegeed on some straight epoxy to seal the micro and fill pinholes.  I’ll add another layer or two, then sand and see where it sits.

I used the excess epoxy to seal the inside of the emp fairing.  I’m hoping to get the rest of the emp tips ready to spray this week, then spray a whole batch of glass one night.  Once the tips are done, the emp parts will move to the hangar.

Drilled the dataplate to the fuselage — I’ll send this in for engraving with the fuel caps.  Also located some 3/32 pop rivets to attach it. Since I don’t know when the inspection will be, I’m just going to put 2012 in the date box; this field isn’t even required.

Then I took a look at the top hose from oil cooler to engine; I think the bend radius on this hose is too tight, and I’ll need to order a longer hose, change the fitting on the engine, and reclock the fitting on the oil cooler, to allow a more sweeping bend in the hose.  It’ll be more in the way of filter changes, but don’t want to take any chances with an oil hose collapsing.

Added a silicone boot to the oil temp sensor wire; more for vibration support of the wire than for short-circuit protection.

Stuck a label on the brake reservoir, indicating what the thing is, and the spec of the fluid it’s filled with.

Traced the spinner diameter and used some geometry to trisect it, in preparation for making the prop cutouts.  Still need to figure how I’ll determine the shape of the cut, not owning one of those curve-finder pin apparatus.

After a trip to the store for more electrical tape, including several bright colors to be more distinguishable from the black colored glass, laid down the first layer of (black dyed) micro mixture on the canopy fairing.  I’ll hopefully sand this tomorrow, then I expect it will take one or two more applications before it’s done.

Sanded & re-drilled the oil door where I had epoxied some misdrilled holes closed.  This is ready for more finish work before riveting the hinge.  Also did some sanding on the top cowling to remove bumps of epoxy and overlap edges of glass fabric.

Sanded the canopy fairing.  Not much of an entry for 3+ hours of work, but that’s the size of it.  Hoped to lay up the first round of micro filler so it could be sanded tomorrow, but it got too late.

Broke out the “fast” hardener and laid up several plies of glass inside the nose of both cowl halves.  Once it cures, the cowls will be mounted on the plane, and the nose sanded back to a consistent distance behind the spinner.  This may require some work on the cowl overlap flanges too, since thickness has been added.  I think I’ll have to either sand the bottom flange (the “inside” piece) back before fitting, or cut the bottom flange off entirely, and lay up a new one once the nose job is finished, which would have the additional bonus of fitting perfectly (using the top cowl as a mold for the layup).

After leaving that to cure, started work on sanding the fwd canopy fairing, which so far is a giant bead of Sikaflex.  It’s tedious to sand, but doesn’t wear the sandpaper at all.  I found several air bubbles as I sanded down, though.  Not sure yet if I’ll leave the Sika as is for now (with a primer for UV protection), or lay up a couple plies of glass on top…those who have gone before report mixed results with the Sika-only fairing — the air bubbles, and possible paint cracking due to the flexibility are of concern.  I need to read up on the process for glassing the fairing.

Long week of work at work, and haven’t really had/taken time to work on the plane.  Looks like flying this weekend will be a bust due to the schedule at the FBO.  Off to the shop tonight to make some way on a bit of fiberglass work; this gets annoying because you can only do so much before you have to put it down and let it sit until the epoxy is cured.

• Laid up 2 plies of glass at 45* to each other on the FAB split.  I’ll let this cure, then add more glass to the inside of the box.
• Brushed on a coat of epoxy over the shaped/sanded micro on the elevator & rudder tips.
• Sanded on the upper cowl inlet ramps until my arm wore out, smoothing the micro that was applied earlier.
• Added a small layup of a couple plies of fabric on the inside of the emp fairing, the top aft side where it is torn (came out of the box that way).
• Filed a bevel on the inside of the air intake snout, the first step of creating the duct that routes the air into the FAB.
• Cut the supplied foam block from the FAB kit in half and glued the two halves together, in prep for fitting it to the cowl snout and FAB.
• Went back to the shop later in the evening and put down another coat of epoxy on the elevator/rudder tips.

Oshkosh week…I’ve been listening to LiveATC all week at my desk, with the flightline webcams running in another window.

Knocked a few more small items off the list tonight:

• Loaded the latest software update from AFS on the EFIS.  The biggest new feature in this release is multi-leg flight planning, but I couldn’t play with that since the GPS isn’t connected up at the moment, so it doesn’t know where it is.
• Did an initial trim of the forward baffles to match the curve of the inlet ramps, just enough to get the cowling on.  Next step here will be the paperclip trim.
• Cleaned the inside of the canopy using some stuff I got from Spruce called “210 Plastic Cleaner”.  I went a little panicky after the adhesive overspray incident, and ordered too many different things for cleaning, polishing and repairing scratches…the second thing I tried took the light fog right off.  (The first one, Permatex Plastic Cleaner, had a gummed up trigger and wouldn’t spray, so I wasn’t able to try it out.)  With the stock I have now, I ought to be covered on canopy cleaning for awhile…

Terminated the lighting wires that emerge from the underside of the canopy structure in a mating plug to the one installed on the subpanel the other day, and covered the loop with nylon sleeving for chafe protection.  Drilled a hole in the center of the glareshield to pass the GPS cable through.  Unpinned the  puck GPS cable from the DB9 connector, so it can be passed through the canopy hole when ready, and put a snap bushing on the cable. Two cables will come from the canopy, the panel floodlight and the GPS, both of which have a disconnect on the subpanel.

Also removed the magnets from the bottom of the GPS puck, and filled the holes with RTV to re-seal the casing, since with the magnets removed, you can see the sensor board and wires inside the unit.  Temporarily reconnected the GPS to the EFIS to verify that nothing was damaged during magnet removal; all appears functional.

Soldered a 3.5mm jack on the end of the cable that’s connected to the passenger phones line of the audio panel, and installed that jack into the bottom flange of the instrument panel, over on the passenger side.  I wired this up to provide a convenient place to tap into the intercom/radio audio with an audio or video recorder.  All audio wiring is now complete.

Worked with the block of black Delrin I ordered to fabricate and install the canopy closure guides.  The idea is that these low-friction guideblocks will capture the latch fingers as the canopy lowers, then align them properly with the holes they must pass through.  By providing a mechanical means for alignment (rather than relying on a human to guide it), the hope is that the possibility of cracked canopy corners or beat-up latch plates will be reduced.  This is a fairly common addition, it seems.

I started with a block of Delrin from McMaster, 1/2″ thick, 1″ wide, and 12″ long.  Measured and marked some guide lines, cut on the bandsaw, shaped on the disc sander, and cleaned up with a razor blade and scotchbrite, ending up with a pair of symmetrical guide blocks that look decent and should do the job.  To secure them, I decided to use #6 hex-head screws.  I drilled the holes, 3 per block, with #27 for the screws, then counterbored a 3/8″ flat-bottomed hole (start with a regular 3/8″, finish with the forstner bit again) about halfway through the block, then pressed in a 3/8″ OD  #6 black stainless washer, which will spread out the screw force, but you can’t tell it’s in there, since the color matches that of the Delrin.  Used the blocks to match-drill the rollbar, then tapped the holes, since getting nuts and wrenches that far up in the hollow rollbar would be nearly impossible.  These blocks are not structural, and they’re plenty solid with the tapped holes.  I think the install turned out well, though I’ll have to wait awhile until canopy installation to see how they actually work.

Used some newspaper taped together to make a pattern for the glareshield covering, then transferred that pattern to the material, and cut.  I’m using a big piece of industrial fabric which is the loop-side of hook-and-loop fasteners.  Essentially, it’s a giant piece of female Velcro.  The GPS puck will be fastened to it by sticking dots of male velcro on the bottom, and any other items that would be handily secured there can be fastened in the same way: wrap a strip around pens, flashlights, and so on.  I left the aft end of the cut fabric long, then fit the piece to the forward edge curve (the inside of the canopy bubble), and wrapped the aft end over the glareshield edge.  Using the pinch welt I got from Classic Aero, I secured the aft edge in place, then cut with a razor blade along the edge of the pinch welt on the bottom side to remove the excess length.  Poked a  hole matching the hole drilled in the glareshield earlier, where the snap bushing will go.  Finally, I flipped the entire piece out, over the pinch welt.  I’ll find some adhesive material to apply to the glareshield, then roll the fabric down over the top of it, to bond it securely in place.

Some days, checking off little tasks can give a good feeling…today was one of those days.  Not much got done, really, but it was nice to call a couple things finished.

The major victory for today was the installation of the secondary canopy latch with spring modification.  I’ve mentioned a bit about this before; today I headed to the hardware store to dig around and come up with some springs that would work.  A found a 5/8″ by 1 9/16″ compression spring that was a perfect slip fit on the 1/2″ shaft of the latch, and had a good strong spring force.  To accommodate the length of the spring (it needs to be long enough to allow the latch to pull down far enough to clear the canopy frame), I chose not to cut the UHMW block down to capture only 2 of the mounting bolts, but rather to counterbore the block for the spring.  Since the 1/2″ hole is already drilled, I used a Unibit to enlarge it to the 5/8″ step, followed by a 5/8″ forstner bit in the drill press to bore the hole to the required depth (I went almost 3/4″ here).  Cleaned up the hole so the shaft slid freely, installed the spring into the hole, and capped with washer and cotter pin.  Pretty slick, I think.  I bolted the latch to the canopy frame, with the latch block spaced out from the frame by placing an AN960 washer on each mounting bolt, between block and frame.  This provided just enough space that the washer and cotter pin have clearance from the frame.  I did find a smaller diameter piece that could be used in place of the washer (sold as a 1/2″ ID x 1/8″ spacer), but the head of the cotter pin still needed clearance.  It’s easy enough to change if needed, but I don’t forsee a need to replace it; the latch arm has plenty of reach to the aft side of the canopy frame, to engage the rear window bow.

Number two: installed a newly-purchased screw to complete the installation of the pitot-static manifolds.

Number three: riveted in the magnetometer mount, and mounted the EFIS 1 magnetometer.  Also slid the elevator pushrod into the tailcone.

And, finally cleaned up the shop, including the massive nest of short wire bits that had collected on the bench…

Trimmed the UHMW block for the top canopy latch, and drilled the holes which bolt it to the canopy frame.  Found a washer that fits the shaft of the latch, and drilled the shaft for a cotter pin, but discovered that the washer’s OD is too large to fit on it; it hits the canopy frame.  I’ll have to dig deeper in the bags, as I must have pulled the wrong washer.  I’m also planning to install the spring modification that others have done, which allows the latch to tuck up parallel to the canopy frame, eliminating the possibility of locking oneself out of the plane if the latch were to slip.

Installed plugs in the open ports of the pitot & static manifolds.  I installed these manifolds to allow for easy expansion in the future, to run lines to a second/third EFIS, autopilot, and whatever new gadget comes along that needs it.  I haven’t found the second long screw I bought to secure these, though…looking like a fresh one from Menard’s.

Installed the center bearing block for the rudder pedals.

Shaped the upper body of the Gretz pitot tube slightly as needed to fit into the pitot mast, put the nutplates on the mast, and installed it to the wing.  Then, installed the pitot tube to the mast after trimming the pressure line and wires as needed, and wired/plumbed it.  I decided to try using a straight quick-connect union to join the 1/4″ copper line from the pitot tube to the nylon tubing which runs through the wing, since they’re supposed to be OK for all types of tubing.  If it doesn’t work, there’s plenty of room and remaining length on the tubes to do it a different way.  With the pitot installed, I rolled the wing cart over to the fuselage and plugged the left wing in, to verify operation of the heater.  Cooling it off with a cupful of ice water caused the heater to kick on, and the indicators indicated appropriately.  Check.

Drilled attachment holes in the rudder cable fairings, then match-drilled them to the fuselage.  I went with one hole in each corner for a total of three; if this proves not enough, it’ll be easy to add two more holes halfway along the sides.  I plan to attach these with blind rivets; easy, and easy enough to remove with a drill if needed later.  Primed the inside surface of the fairings and left to dry.

When testing the pitot heater, I had all three of the annunciator lights lit up on the panel, and grabbed a couple photos.  I really like how these LED indicators worked out, even though they were a bit pricey.  They may end up being too bright at night, but with the way they’re wired, it would be simple to add a bright/dim switch, or even a dimmer pot.  And, they should be dark in the normal condition, so it may be a non-issue.  (The camera makes them look brighter than they actually are, too; the hotspots in the photo aren’t apparent to the naked eye.)  I’m still very happy with the panel design & layout; putting that together was, as expected, one of the highlights of the project.

Spent a bit of time fussing with the control cables again.  I didn’t come up with a bracket solution that satisfied me, because the too-short mixture cable would need it’s bracket a couple inches closer to the firewall than the throttle.  The extender wouldn’t solve that, just make it reach the lever.  So, I guess I’ll order a longer custom cable, wait for it, and get it in right; then sell the short one to someone who can use it.  Also, more aluminum angle to redo the bracketry.

Cut the side hinges and hinge shims that will hold the lower cowling, and drilled them to the firewall.  Marked and cut the slot in the cowling for the gear leg.  Cleaned up the fiberglass on the backside of the nose flanges and refit the cowls together.  Clecoed the top cowl back on the plane, then put the bottom cowl on via the two clecoes in the nose, and a cargo strap under the rear portion.  The fuselage end seems like it will fit decently, but the nose doesn’t hold alignment with the spinner backplate — the gap at the top right side is 1/4″, and the lower left is 1/2″.  This might close up a bit with the rest of the fitting, but it looks like a load of filler will be required.  (Apparently this is not uncommon.)