Joshua's RV-9A Project

Attempted to finish up the final tasks around mounting the wings tonight, in an effort to get at least one garage bay open for parking again.  First up was drilling the wing root fairings, which turned out to be relatively easy.  The fairing is pre-drilled all along it’s length, and the holes match up with open holes in the wing top skin.  Once in place, the holes are match-drilled into the edge of the fuel tank skin.  Then the bottom fuselage skin is drilled to the wing skin, with the aid of guide lines drawn on the wing skin before mating the wings.  I first drilled all the holes to #40, then enlarged to #19 for the #8 screws.  Once the wings are removed, these holes will be prepped and nutplates attached.

The other remaining task was to fabricate and install the F-996A fuel tank attach brackets, which mate with the beefy angle piece built into the inboard nose of each fuel tank.  Cutting and shaping these was straightforward if tedious (due to the 3/16 thickness of the angle), but the bending appears to be the tough part…clamping them in the vise and using a crescent wrench (a la longeron bending) did nothing, nor did whacking them with a hammer and wood block, or attempting to compress them in the vise (as we do in other places when narrowing the spread of a piece of angle).  Reading the typical online sources, it appears I just need to hit them harder, so that’ll be tomorrow’s task.  Tonight, I’ll double-check that everything is done that needs doing before pulling the wings.

No work on the project for nearly a month, though it’s been near in thought.  Times have been busy at work pushing toward completion of a complete remodel of our audio production studios, and life has happened in other areas, as well.  In the meantime, Vertical Power shipped me the new blank box for the VP-X Pro (the other one is on the way back), and I bought some vise-grip clamps for drilling the rear spars.  That’s about the entire progress that was made on the project; the upside is that the credit card bill this month will be gloriously small.

Tonight I pushed over the next hurdle, hoping that things will mellow a bit for at least a few weeks and allow some work time…the engine and interior should be coming early next month, and the icy season is dead ahead, so I need to get the wings off and restore some garage parking.

After checking the fuselage for level fore-aft and laterally, I trimmed a block of hardwood to a bit larger than the spacer required for finding the wing incidence, and fine-tuned it’s length with the disc sander.  With the block of wood securely taped to a 4′ level at the correct distance from the end, and a bucking bar taped at the far end to hold it on the wing, I was ready.  Setting the wing incidence was easy; both were very close to start with, requiring only a small adjustment upward, and a push to be sure the rear spar was fully seated in the “hand” of the fuselage.  Clamped down and measured in several locations along the wing, then marked the infamous 5/8″ edge distance on the spar stubs (a piece of scrap filed to 5/8″ made marking easy…I actually cheated for extra safety margin and used a 21/32″ strip, and the width of the marker line made it more like 11/16″…).

Satisfied with the rigging, I test-fit the flaps as suggested by Van’s in their incidence drilling guide.  Both flaps required filing off a small portion of the inboard nose skin to clear the spar stub for full retraction, but the bottom skin tucked nicely against the fuselage bottom.  Flaps off, I went in and re-read the drilling guide from Van’s.  A couple more measurements, and it’s time to get on with the drilling.  “Nothin’ to it but to do it,” as they say.

The actual deed was done easily.  A long #30 bit and a drill guide made from a block of oak set the pilot holes in the center of the edge-distance box.  Stepped up the holes with a series of drills to final size: #30, #20, #10, .250, .295, then the .3115 reamer for final fit on the AN5 bolt.  A touch of deburring and in went the bolts.  Done.