I added some more epoxy and filler to the tail fiberglass tip fairings, and while that was curing I spent some time wrapping up additional finish items.
I started by marking the wing root fairings for a 3/16th” gap. I marked the fairing with some black sharpie, and then used a 3/8″ bolt to score a small line, resulting in a 3/16th” gap from the side of the fuselage. I then removed the fairings from the wings and used my snips to cut back to this line. I then filed this edge to smooth out the cut. After this I installed the rubber seal that will bridge this gap, and reinstalled the fairing to the wings.
After this I spent some time inside the cabin installing support braces for the panel. Originally, the design has two large ribs that extend from the firewall all the way back to the panel through the sub panel, making the entire structure very rigid when riveted all together. With my panel design however, I removed those ribs between the sub panel and the panel so that I can fit all my avionics. As a result, I needed to fabricate some new supports that I can install between the sub panel and panel so as to not lose any rigidity. I fabricated the supports out of some 3/4″ angle stock, and cut to length so I could use my avionics trays as the anchor point on the panel, and then drilled two holes through the sub panel for a screw to hold the supports.
While I was in the cabin, I finished securing all the wiring below the seat floors and in front of the spar. Additionally I also added rubber edging to the fuel line passthrough holes in the sides of the fuselage so the steel braided hoses won’t rub against the fuselage. I will additional silicone tape around the hoses to make an air tight seal (or at least more of a seal).
I also added the four remaining wing spar bolts. They are AN4-13A bolts that are inserted from the aft side of the center-section spar into some nutplates on the wing spar. These bolts are often missed as they are not part of the larger main bolts that go through the entire assembly. (The paint marker got a little runny)
I began wrapping up the interior controls installation by adding all the necessary washers (which are pain to install) to the Aileron Pushrod – to – Control Stick attachments. This included tightening the jam nuts on all the pushrods and ensuring that a sufficient number of threads are available on either end to ensure that if something does come loose, nothing can fully unscrew. I then marked everything with torque paint.
While I had the floor pans out and working on the aileron pushrods, I decided to install the aileron pushrod boots. These are leather covers that attach over the pushrods to prevent air from entering the cabin. They are from Classic Aero Designs and were quite easy to install. The provided instructions are very clear. Another great product to go with my complete interior!
In parallel to all the above items, I began working on some of the fiberglass parts on the plane. Starting with the Horizontal and Vertical Stabilizer tips. They are pop-riveted to the surfaces, and have some foam and fiberglass filling to close gaps around the attachments. I also filled the gaps and glassed over the joint after riveting them to the surfaces. This is an iterative process and the epoxy curing time allows for a lot of work to get done in between. I’m using the West System Epoxy 105A (and 205A hardener). They make it super easy with the pumps – 1 pump from each is exactly the amount for proper mixing. This is going to take a few iterations to complete, but once the surfaces are bonded and glassed, I will paint over them with some primer to seal the whole thing.
February has been a bit of a slower month in making big progress. I’ve spent a few evenings working on several different things. I got some new shelving units from an old storage unit that my mom was getting rid of, and they sat in the hangar for a few weeks before I finally got some time to assemble them and reorganize a lot of the stuff we have.
I spent an evening with my wife moving the old shelves and workbenches to opposite sides of the hangar, and moved the new shelves to the back wall (they’re much bigger) and just general organizing of tools and parts and a lot of clean up.
We also made a trip to the Container Store and got more plastic boxes for stuff. Its always satisfying when putting things back on shelves and seeing how organized it is at the end.
I came back a few days later and worked through a short to-do list of things inside the plane. I needed to shorten the elevator pushrods so that the bellcrank would rotate aft a small amount. When I pushed the elevator fully forward, it would get a little “squishy” and if I pushed harder, it would then hit the forward (down) stop. I figured the only thing that could be causing this is that I was over rotating the autopilot servo, which is attached to the bellcrank. After shortening the pushrods, I reinstalled everything and tested the forward (and aft) stop, everything hit their stops with no problem or squishiness felt anymore. I then torqued all the bolts and marked them with torque paint.
As I was working on the larger aft pushrod, I noticed that the aft fuselage skin still needed to be riveted. Its the portion right under the empennage, totaling ~50 rivets. I’m surprised I didnt notice this earlier, but It would have been caught when I started doing the fiberglass work on the empennage fairing. I realized I needed to remove the horizontal stabilizer in order to sufficiently gain access to rivet these holes. I proceeded to remove the tail and then riveted the aft skin with no issues and then reinstalled the vertical and horizontal stabilizers.
Now that I have the elevator and rudder off the plane, I will be working on the fiberglass tips.
Today I spent most of the day working on a bunch miscellaneous items.
I started by fabricating my aileron stops. I am using a small delrin bushings around the aileron pushrod spacer to act as the stops.
Aileron stop bushing
After fabricating and installing I measured the deflection angles – I have 28 degs up and 16 degs down for each aileron. The specifications call for a minimum of 25 deg up and 15 deg down, so I’m within the standard range.
Left aileron neutralLeft aileron upLeft aileron downRight aileron neutralRight aileron upRight aileron down
Next I drilled two holes in the fuel tank mounting bracket in order to attach the safety wire. These bolts are tightened snugly with a large washer in order to allow for separation from the fuselage in the event the wing is hit. The safety wire will prevent the bolts from prematurely backing out.
I also made some slight modifications to the position of my accessory bus fuse block. I needed to modify the position lower in order to allow for the forward top skin to be installed. I’ve modified the top skin with the optional access panel kits. The panel is held in place with nutplates and the bottom of the nutplates interfered with the fuse block. Now that I’ve lowered the position the top skin is ready to be installed.
Last but not least, I also secured the pilot’s stick wiring harness connectors, among other wiring bundles below the seat skins.
I spent some time over the weekend beginning the installation of my Classic Aero Designs Sportsman II interior with Aviator seats. There are two things I want to call out about Classic Aero – 1. the customer service and overall experience working with them over the last couple years (ordering, receiving, installation) has been great. And 2. the quality is impeccable. Everything is superb in fit, and finish, and it really makes the plane feel like a premium aircraft.
I received some guidance on the installation process, so I began by laying out the carpet in the plane to mark the locations. I then installed the velcro chips (Velcoins) that are used to hold the carpet down. They are pop-riveted to the floor pans and then the carpet is attached.
I then proceeded to install the seat backs, cushions and stick boot covers to really get a sense of what the interior will look like.
In the next few days I will install the remainder of the interior (for initial fitting) including the side panels, pockets, armrests, forward carpet, baggage carpet and baggage side panels as well as rear cover. It’s really starting to come together!
After rigging the ailerons and flaps and making sure everything was aligned, I needed to remove the wings one more time in order to finish up some critical items. The to-do list included finishing the Root Fairing seals and drilling two more holes for the Pitot and AOA tubes (for the left wing). The Root Fairing seals have about 20 nut plates that need to be riveted to the wing in order to accept the screws that hold everything together. This required removing the wing so I have access to the inboard rib of the wing to install everything.
A few years back, a fellow builder, Vince, told me about a solo method to remove and install the wings using the wing cradle. If it wasn’t for this guidance It would have been quite annoying to attempt this work by myself. The method involves putting the wing cradle under the wing when its temporarily installed in the plane, and then using some plywood clamped to the cradle to prop the wing up in its final orientation.
I used some scrap plywood my friend Norio gave me, and cut it to size such that when clamped to the cradle, it fit snuggly under the wing. I then clamped everything and tightly as I could. I hopped into the plane and began the painstaking process of removing the bolts that had been temporarily holding the wing on. Its quite a tight and awkward fit, but I managed to remove everything. I then slowly removed the wing while it was held up by the wing cradle. Success!
Once I had the wing off, I began the process of drilling, countersinking, dimpling, and installing the nutplates to the inboard rib of the wing. This was pretty straightforward, nothing too challenging here.
I also used this opportunity to drill two additional holes in the side of the fuselage for the pitot and angle of attack lines. Its all quite a tight fit inside this area, so trying to make sure I had everything lined up appropriately. When I initially installed the lines, I mistakenly cut one of them a couple inches too short. In this pic you can see a short segment that is used to attach everything. After taking this pic I added a longer segment in the wing under one of the access panels (where its easier to work) in order to remove this short segment under the floor pan.
I Also needed to attach the nutplate to the fuel tank bracket. This is an AN4 bolt that will slip away in the event that the wing impacts something, in order to prevent the fuel tank from rupturing to minimize the risk of a fire. The bolt here will be safety wired.
Once I had everything drilled, and all the nutplates installed, I reinstalled the wing. The wing cradle method worked absolutely flawlessly, and makes installing the wings solo completely reasonable. I then installed all of the bolts that hold the wing, as this is the final time the wings will come off!
The next day, I went back to the hangar to repeat the entire process on the right wing. This one took me about 50% less time, which was nice. Now that the wings are permanently installed, I can now wire up the wingtip lights, and autopilot servo, which will close out the two remaining avionics to-do items.
This weekend I hit a huge milestone – my buddy Norio and I installed the wings on the plane!
We started by first leveling the plane to make sure we had the ability to, as well as thinking it would make sliding the spars into the fuselage easier.
Once the plane was level, we began the process of installing the wing. Once we got the main spar on the left wing mostly installed, we needed to make quite a few adjustments in order for the bolt holes to line up. We eventually got the correct dihedral angle which caused the first bolt to slip in nicely. I kept the bolts in the freezer overnight to help shrink them a little, then applied some lube to aid in the bolt install.
I hopped into the cabin to get the second bolt inserted. It took a bit of coercion, as I think there may be some micro-misalignment with the fuselage structure causing quite a tight fit. I used an alignment pin that I built using some store-bought hardware. it definitely helps to get the spar in the right spot.
Once the second bolt was in, I got out and Norio was able to let go of the wingtip. The plane now had one wing! The whole process for the first wing took about an hour, because there was quite a bit of figuring things out with respect to angles and alignment. After taking a quick break, we jumped onto the second wing. At this point, my wife joined us and helped get the second wing installed in about 20 minutes. It was much smoother.
Once both wings were installed with a couple bolts, we began the rigorous process of measuring wing sweep, incidence, and symmetry. We started by first using a laser level to mark a straight line on the ground spanning the wings, that will be used to measure sweep. We then hung four plumb bobs off the leading edge of the wings and began to align them with the laser line. We also aligned the fuselage longitudinally with the laser, so we could later measure the squareness of the whole plane. At this point, we measured the sweep, and both wings were about 1/4″ swept forward. Van’s calls for fore/aft sweep within 1/2″ from center, so it was already within spec, but I knew we could make minor adjustments to achieve a closer sweep angle. A few iterations of adjusting the rear spar, and we got the sweep to within 1/8″ of an inch. This equates to 0.2deg of sweep!
After getting the sweep right, we clamped the rear spar attachment in place. Then we checked the incidence angle. The incidence is measured by spanning a level from the forward spar to the aft spar with a 3″ space above the aft spar. If this angle is 0 deg (or matches the fuselage angle – which was level at 0 deg) then the incidence is correct. Van’s guidance is not so much the precision of 0.0 deg incidence, but that the two wings match. In my case the initial measurement was 0.3deg off from 0 on the left wing, and 0.4 deg on the right wing. At this point we made some minor adjustments by unclamping the rear spar and adjusting it downwards. this brought the angle on the left wing to 0.0deg, and the right wing also to 0.0deg! We clamped the wings, double checked the sweep, and also took a measurement from the wingtips to the aft center of the fuselage. Both those measurements were equal to each other. At this point we wrapped up for the day.
The next morning, we came back and double checked all the measurements with a fresh eye. Everything still measured perfectly. I got out my drill guide and drilled a #30 hole through the rear spar on the left wing. The center of this hole was > 5/8″ from all edges of the rear spars (on both wings) per the structural requirements. I then expanding it to a 1/4″ hole using the guide. After a 1/4″ I drilled the spar to 9/32 and then used a 0.311 reamer to finish the hole. The reason for doing this step is that the bolt is an AN5-10 bolt (measures 5/16″ in diameter), but the hole made by a 5/16″ drill bit is slightly bigger (a few thousandths). For the primary bolt that locks position of the wing, it should be a super snug fit. The bolt measures 0.3125″ in diameter, and the reamer is 15 thousandths smaller than the bolt. We did the same thing on the right wing.
At this point, we called it a day, but I got out the aileron pushrods and inserted them into the wings in preparation for rigging the controls. Similarly with the flaps, I temporarily installed the flaps to ensure that they could fully retract to the underside of the fuselage. Next time I’ll finish the aileron control rigging and flap rigging.
I came back the next day to see how the window set up. Everything turned out perfectly. I removed all the clamps and check the alignment with the canopy. The gap was just around 1/8″ of an inch. I got all the tape removed and then set up some more SikaFlex to create a nice fillet on the front of the window all around the rollbar.
I was very eager to see how the window looked without the plastic, so I removed it. It looked very very clean. Really started to make the plane look more like a plane.
Now that the canopy was done, and the rear window was done, I also decided to remove the plastic from the canopy. This was a huge milestone and nearly 8 years in the making (Quickbuild kit? What Quickbuild 🤣).
One last thing I had been meaning to do (and probably should have done a long time ago) was to fabricate and install the forward canopy brace clips. I don’t have a picture of them, but they are small 1/2″ wide pieces of aluminum that are riveted to the inside of the canopy brace just to add a little bit more rigidity to the canopy frame.
Today I installed the side skirts to the canopy. I began by completely prepping the surfaces of both the skirts and the canopy/canopy frame. Since I bonded the canopy to the frame with SikaFlex, I also am bonding the side skirts to the canopy. This requires following the same steps as before: activator, primer, glue.
Once I had all the surfaces prepped, I applied the activator and then waited the required 10 minutes. then I primed both surfaces and waited 30 minutes. I then applied a generous amount of glue and spread it out, then I clecoed the skirts in place. I needed to add a clamp to the top corners on either side, to get the skirt to sit right against the canopy.
While things were setting up, I also decided to wire up a tail-mounted forward-looking camera. Years ago I added wiring provisions for adding a tail-mounted camera, but did not know what I would do in the long run. I decided to mount a wide angle mini camera to the top of the vertical stabilizer.
I wired the camera up and fed the signal into the Dynon EFIS. I spent some time working on the alignment, and once I was satisfied i tacked the camera in place with some super glue.
I will eventually build up a fiberglass and epoxy fairing to smooth out the transition to the camera. I will also likely need to make this removable, but thats for another day.
With the Aft fuselage skin riveted in place now it was time to fit the side skirts. I needed to fabricate the two sideskirts out of some stock aluminum. They needed to be trimmed down to the required dimensions and then aligned with the aft skin. This took some iterations, but eventually I got a nice fit. Once the parts were temporarily taped in place, I began drilling the skirts to the canopy frame.
I used my rivet fan to get perfectly spaced holes, and drilled the skirts to the canopy. I needed to use some small washers in between the skirt and the frame near the front section in order to get the proper spacing and alignment with the side of the fuselage.
Once the skirts were fully drilled I removed the skirts and countersunk all the holes in the frame, and dimpled the holes in the skirts.
I also fabricated the canopy handle and marked and drilled it to the skirt and frame.
RV-7 N890GF 