My original plans with the control sticks was to use Infinity Aerospace stick grips. Unfortunately, no amount of trimming of the stick base was enough to create clearance from the throttle and mixture controls with these stick grips. If I had installed a throttle quadrant instead of the standard vernier controls, they would have worked out.
So I went with plan B and bought the standard Vans stick grips. These provide *just* enough clearance from the throttle and mixture controls, and they clear the bottom of the panel. There is still interference if the cabin heat vent is on and the stick is in the full forward and left/right positions, but there really isn’t anything I can do to avoid that.
The sticks just needed to have their base holes drilled, and the wire harness connectors replaced with my setup, and they were ready to install.
Holes drilled and connector replaced. I bought a spare stick base to serve as a drill guide for drilling these holes. I wasn’t going to try to drill them in place, and didn’t want to take the stick bases out of the airplane.There are fewer switches on this stick, but enough for what I need.
This morning I finished out chapter 41 (wing attach) by installing the fuel vent lines. I opted for Aircraft Specialty vent lines, just to save some time and effort, and I also installed the JD Air fuel vents.
The standard Vans fuel vent design has a fuel line passing from the tank down through the wing fairing, where it’s chamfered at 45 degrees. I’m sure this works great, but there are a couple of downsides. The line has no screen, so there’s a risk of insects or dirt making its way into the fuel line, or even the tank, and causing an obstruction. There’s also a chance I’ll snag the vent on something and damage it. JD Air makes a streamlined vent with a built in screen, so I installed these instead. Aircraft Specialty makes a fuel line that fits the JD Air vent, so that was very convenient.
The vent itself attaches to the bottom wing root fairing using a bulk-head fluid fitting, so it simply screws into position. I was then able to loosely install the fairing, position the fuel line, final torque the fairing screws, then torque the b-nuts on the fuel line to secure it in place.
Everything went well, the only bummer is the gap at the aft end of the fuel vent, caused by the curvature of the fairing. It’s no big deal, it’s just cosmetic, and no one will see it unless they look for it specifically.
I also installed fuel placards and some grip tape on the pilot side of the wing walk area.
After a weeks off for the holidays, I was able to make some more progress this week.
I finished the wing root fairings, and installed the wing root fuel lines. These are the lines that connect the fuel tanks in the wings to the fuselage.
The wing root fairings were fairly straight forward. Getting the right shape on the bottom fairing was probably the biggest challenge.
Soon after getting the shape right I realized that I needed to countersinking the holes on the tank attach bracket. And then I noticed I had more containing to do on the wing top skin, so that the top fairing could be installed.
I brought all my countersinking, drilling, dimpling and riveting equipment to the hangar today and knocked it out. The countersinks are a little tricky because the nut plates are already installed, so a #8 countersink (the correct size) doesn’t work because the pilot interferes with the nut plate threads. I used a #21 count sink bit which seemed to be just the right size to fit into the nut plates. The countersinks are fairly deep because the fairing has #8 dimples that need to nestle down into the countersinks. The aluminum stack up is several layers deep, so there is plenty of material to support the counting depth. The only tricky part was the top, inboard countersink on the tank attach bracket. This was too close to the fuselage to get the counting cage to sit vertical, let alone the drill. I rigged up a long extension, about 18 inches long, a drilled those countersinks without a cage. It was quite easy to see the depth and I just went little by little until it was done.
There are some holes that need to be match drilled, and then 3 nutplates installed on each size. I drilled, dimpled and riveted these.
I found some proseal and used it to glue down the wing spar spacers, after giving them a little shape to conform to the wing skin.
The fuel lines were next on the list. These were pre-bent by Aircraft Specialty, and they fit exactly right. The time consuming challenge was finding a way to get them into position. The line is short and quite inflexible, and the flared ends, which are easily damaged, mate to the aluminum fittings on each side.
I loosened up the fuselage side fitting so I could flex it inboard and create enough space to insert the fuel line. I had to use a wedge to push and hold the fuselage fuel line out of the way enough to insert the new line. Once the line was in position, I torqued everything up and it all looked good.
The three nutplates that I installed, this picture is of the right hand side, it’s a mirror image on the leftClose up of one of the nut platesCountersinks on the top of the tank attach bracket. The one at the top of the image is close to the side of the fuselage and hard to reach. The spacer glued into position on top of the wing spar. This hard plastic block supports the upper wing root fairingTop fairing installed on the left sideThe underside of the bottom fairing. The screw in this position grazes the end of the wing spar. Rather than installing a full length screw, I plan to order and install some shorter screws that will stop short of touching the sparThe fuel line in place. The wing tank is on the left, and the fuselage is on the right. B-Nuts are not torqued yet.Looking down at the left hand side fuel line After torquing the B-nutsEarly morning at Ramona after a rainy night
Not much progress this week. I focused on switching out the connectors for the landing lights, and then installing the landing light lenses.
The original landing light wiring setup used molex connectors for the three wires providing power and ground to the Landing and Taxi lights. I was never very happy with the crimps on the wires, the poor connection, and the awkward angle of the wiring entering the molex connector.
I decided to replace them with DTM connectors, and re-route the wiring. DTM connectors provide better wire support, are water resistant, and have a much more positive connection and locking mechanism.
I removed the landing light clusters from both wings, brought them home and switched to DTM 3-wire connectors. Once I had them re-installed in the wings, I tested the lights and then installed the landing light lenses. The wiring setup is much more robust now, and I’m sure it will work out well.
I spent some time on the wing root fairings. Each fairing consist of two parts, an upper and a lower fairing. The upper is thicker and covers the area from the flap to just forward of the main wing spar. This is designed to be walked on when entering and existing the cabin. The lower fairing is thinner and longer, and covers the bottom of the wing, and wraps around the leading edge. Forming the curve around the leading edge was a bit time consuming. The plans explain the initial bend, which is easy enough, but then some careful manipulation by hand is needed to get the final shape. It took an hour or so to get the curve right on both sides.
There are a few more steps to finish these fairings, including riveting on a series of stiffeners.
Landing light bay with the new DTM connector visible. Wing root fairings on the left wing. I was test fitting these, getting the bend right before installing stiffeners and dimpling holes etcBottom wing fairing where it bends around and forms the leading edge.
I didn’t have much time this week, but I was able to get the trim system working correctly.
Using the laptop and a long Ethernet cable I was able to use the VPX configurator tool on my laptop to send power to the trim motors. I was pleasantly surprised that both the roll and pitch servos worked correctly. I carefully verified that the orientation was correct. It would be easy to reverse either one. For example, the elevator trim tab moves up and down just like the elevator, but it has the opposite effect from the elevator itself. Pitching “up” causes the elevator trailing edge to move up. Trimming “up” causes the elevator trim tab to move down, not up. It moves opposite the elevator, providing a force that moves the elevator to change the aircraft’s pitch.
After confirming the motors were working, I was able to set the correct max, min, and midpoint settings for both servos.
I then worked on mounting the aileron trim brackets on the right wing aileron pushrod. These connect the springs from the servo control arm to the pushrod, actuating the aileron.
Aileron trim servo. The servo mounts onto the access panel at this point. Springs will attach to the holes in the end of the arm, and extend to the brackets on the pushrod. Diagram of the aileron trim system showing the springs and how they connect to the pushrod and servo armUsing the laptop to run the trim motors and to set the trim limit parametersVPX config tool. The whole electrical system can be configured and activated from the laptop. The blue Ethernet cable is a 50 foot cable that plugs into the VPX box behind the panelDue to interference between the springs and the pushrod, I bent the servo arm to gain some clearance Springs attached to the servo arm.One last picture before closing this up. Note, the d-sub connector is safety wired together
This week I’ve continued with various assembly tasks.
Lighting:
I resolved the issue with the strobe lights, finding I had mis-pinned a molex connector on the wingtip. Once I corrected the pins, everything worked just fine. It took longer than I care to admit to troubleshoot and find the problem. I learned that it’s useful to start by validating assumptions around where your wires are going by measuring impedance and verifying there is a good electrical connection. Then start measuring voltage drop, once you know your wires are going where you thought they were going.
Comparing this picture to the diagram below, you can see the difference in the pinout. This is actually how I left the connector. Previously the female molex connector actually had the correct pins, but the male was incorrect. Rather than switching the male pins, I just changed the female. How it’s supposed to be wired. I had the right hand side of this correct, and the left hand side incorrect. I changed the right hand side to match the left .Lights are all working as expected now.
Aileron Attach:
With help from a saw horse with adjustable leg height, I was able to quite easily install the ailerons. I used new hardware, except for the bushings, since I’ve had these on and off a few times. I was wondering if the install would be more difficult than when the wings were in the stand, but I found it the same, or maybe slightly easier.
I installed and final torqued the aileron pushrods, verified they were correctly rigged using the templates. The templates allow for the pushrod between the aileron and the bell crank to be correctly sized to establish the correct neutral point. Later in the week I rigged the stick-to-wing root pushrods per chapter 41, and adjusted pushrod length until I had the neutral point on both ailerons aligned with a level stick base. I was then able to test the stick clearance, and found I need to trim more off both sticks to avoid hitting the throttle (pilot side) and mixture (passenger side).
I hung the flaps and connected the pushrods, adjusting them to get both flaps all the way up, then verified they have enough clearance from the fuselage.
I also secured the wiring for the magnetometer. I had installed this a couple of years ago but hadn’t finalized the wiring. I had plenty of length so I created a large service loop and secured it out of the way of the pushrod.
Flap pushrodsCalibrating the pushrods took an iterative approach but I eventually got itWing tip template helps keep the aileron neutralFlaps on and configuredGetting the washes onto the bolt that secured the pushrod at the stick base was a challenge. Note, this picture was taken before I torqued up the nutPassenger side stick interferencePilot side stick interference
This week I made multiple trips to the hangar to work on various tasks.
Wing attach bolts
I finally torqued the wing attach bolts. The night before, I tested out my torque wrenches to ensure they were reading correctly, and they were both very close. I used a vice to hold the wrench, and then secured a weight over the arm and measured the distance from the fulcrum. For weight I used a 1 Gallon plastic jug filled with carefully measured amounts of water. The nuts were easy to torque, I only found one where it took a second to figure out how to torque it. I ended up using a socket extension that allowed some movement, so I could torque the nut without fear of bending small bits of aluminum that were close by.
Pitot tube:
I finalized the wiring and install of the pitot tube. I used butt splices to connect the pitot heat wiring, replacing the original molex connector. In the process I included a service loop to help with any future maintenance.
I also trimmed the pitot and AOA pneumatic lines at the wing root, inserting them both into the connectors under the seat. I still need to test the system for leaks, and to verify I didn’t switch Pitot and AOA at any point in the system.
Strobe lights:
I did some troubleshooting on an issue with the wing tip strobe lighting. Both sets of strobes are flashing, but weakly. There is only 6.6V at the wingtip, so I’m losing half the voltage somewhere in the system. I tried the easy tasks such as unplugging and reconnecting connectors, but no luck.
VOR Antenna
I completed the VOR antenna wiring, and was happy to tune in a nearby VOR and see a positive ID and a needle on the CDI. The reception seemed good, even though the antenna isn’t well grounded (I don’t have all the screws in the wingtip, and they provide the ground path). The job was quite simple, I just needed to cut the cable to length and install a BNC connector, then plug it into the fitting I had previously installed under the passenger seat. I added a service loop, for ease of maintenance. At the right wingtip I connected the ring terminals to the antenna and torqued them up. I also tidied up the wing tip wiring and then secured the wingtip fairing. I then fired up the instrument panel, turned in the Julian VOR and was happy to see the reception, even on the ground in a metal hangar at 20 miles, and without a properly grounded antenna.
The main spar wing attach bolts, final torquedOne of the aft wing attach bolts Signs of life from the VOR antenna. The Nav radio is tuned to 113.75, and the green line on the left hand screen (PFD) is pointing to the VOR station The VOR antenna connection under the passenger seatRight wingtip wiring. With the wingtip off, I found I could rotate it and set it on its aft edge, balanced against the wing. This made working on the wiring much easier.Service loop for the pitot heater wiring. Insulated butt splices are visible here and would be the recommended place to disconnect the pitot wiring for any maintenance Another angle of the pitot tube install. Note, the pushrod is disconnected to allow more room to access the pitot tube wiring.
Over the course of a couple of evenings this week I checked out the lights and installed the pitot tube, checking the heater function. I’m trying to fully test the electrical system so I can start troubleshooting and addressing any issues.
The pitot tube installation went mostly according to plan. The Vans plans include a simple, unheated pitot tube, and a lot of builders opt for an upgraded pitot tube with AOA and heat, as I have done with the Garmin pitot tube. One of the considerations for the builder is how to bend the pitot and AOA aluminum tubes coming out of the top of the pitot unit to avoid interference with the aileron push tube. My bends were good, and no changes were needed. Installing the 90 degree aluminum fluid fittings was a bit challenging as access is somewhat limited. I was able to torque them sufficiently so hopefully they won’t leak.
The pitot mast and tube during installation. You can see the end of the pushrod emerging from the darkness directly above the pitot mastA blurry picture of the aluminum pitot and AOA tubes bending around the pushrod and connecting to the flexible tubes via 90 degree fluid fittingsI had chatGPT clear up my blurry photo above. Not too bad, although it’s added some details that aren’t in the original
The wiring was where I ran into a problem. I had previously set everything up, and all I needed to do was insert the crimped pins into a molex connector, then plugging it in. Unfortunately, the pins were slightly too large for the molex connector, and in the process of trying to make it work, one of the pins pulled off the wire. I’m going to need to redo the wiring, so I’ll be looking into other options. I may just use butt splices and ditch the molex connector. I was able to rig it temporarily so I could test the heater unit using the panel switch, and everything worked as expected.
The rest of the aircraft lighting mostly worked as expected, although I had a list of squawks to troubleshoot and resolve. The first issue was the FlyLED Combo spotlights on the right wing were not illuminating. This was a lost connection, and fully seating the molex connector resolved the issue.
The second problem was the tail light not working. This turned out to be an inadvertent switching of the wiring polarity, and switching the pins in the tail fixed the issue. I had previously wired up a small molex connector and successfully tested the tail light. What I hadn’t considered at the time was that the wires need to pass through a small hole in the Vertical Stabilizer, and I had to remove the molex connector. Rather than messing with a molex connector (just another possible point of failure), I used d-sub pins and insulated the pins with heat shrink. This is when I had switched the wires and introduced the issue. The biggest pain was the lack of access to wiring. With the tail spring right under the forward end of the tail fairing, the fairing can only be moved about half an inch, and I had to flex the side of the fairing to reach in and grab hold of the service loop and then remedy the issue.
That leaves two lighting issues to troubleshoot, 1. One row of red LED position lights isn’t illuminating and 2. The wing tip strobe lights are very dim.
I reached out to Paul at FlyLED and he has pointed me in the right direction to start troubleshooting to isolate the problem. Hopefully some investigation will identify the issue and I can get these problems resolved.
With the navigation and landing lights on, the lighting is extremely bright.
Next I’ll be testing the trim system, and eventually the magnetos.
I also heard back from Vans about an interference issue I’m seeing between the fuel tank bracket and the fuselage side skin. I’m planning to trim the corner off the bracket, which I hope to do with some careful use of a small cutoff wheel.
The red circle indicates the area where the tank bracket is contacting the fuselage. It’s the same on both sides, so it doesn’t appear to be caused by a wing alignment issue. I plan to trim the corner off the bracket to create some space
Today my friends Jeremiah, Trey, and Sam helped me mount the wings onto the fuselage. Everything went well, and it’s now looking like a real airplane!
I arrived at the hangar early, and spent time preparing for the event. Jeremiah drove down from LA, and within 5 minutes of his arrival, Trey and Sam landed after flying in from Carlsbad. We got started right away, and things went according to plan.
To prepare for the operation, I had laid out all the necessary hardware, plus the lubricants needed, and the tools I planned to use. I chocked the wheels and raised the tail into a level attitude, and set up some sawhorses to support the wing.
We started by lifting the left wing onto the saw horses and fine tuning the height by removing layers of padding. I then applied Boelube and we gently moved the left wing into position. The drift pins went in with some gentle tapping, as did the larger bolts. Then the remaining bolts were driven through, and the job was complete. It was a fun moment of truth to remove the sawhorses and marvel at how simple the attachment was, and how much load the bolts will carry.
We then moved onto the right wing and repeated the process. Generally it was easier the second time, because we had the process down, and knew where to position everything. It took slightly longer to align the right wing, but there were no issues installing everything.
The only potential issue I observed were there tank attach brackets. The aft corner of the bracket is contacting the fuselage side skin. Items the same on both sides, and it could be “as designed”, but I sent an email to Vans to check.
I haven’t final torqued the bolts yet, but this can wait for a day or two, as the bolts are loaded in shear vs tension.
Raising the tail. It ended up even higher than this picture shows.Lining up the left wingLining up the left wingThe 2×4 helped tremendously to tap home the bolts. Not a lot of force needed, just some gentle bit firm tapsThis time on the right wing, Trey applying some pressure to keep the spar web from flexing as the bolt threads pass through.Both wings attached!Amazing to see the airplane almost completely assembled now. Certainly a huge milestone todayThe tank attach bracket. The aft corner of this bracket it touching the fuselage side skin
Over the last week I finished up the tasks needed to mount the tail components. This included removing and modifying the Vertical Stabilizer fairing, connecting the tail wheel, final torque for the rudder attach bolts, and installing the rudder bottom fairing.
I popped the Vertical Stabilizer fairing off, and took it home for modifications. I needed to shave about 1/8th off the back edge, which necessitated adding some layers of filler and glass inside the fairing, to build up the aft edge. Then using a curved sanding block, removing the required amount of material from the back edge. I did all the glassing and sanding at home, then test fit the fairing, made another adjustment, then primed and riveted it back into position.
Then I installed the rudder attach hardware and torqued the nuts on the attach bolts. There’s no easy way to get a torque wrench onto the nuts, so I did the best I could to achieve the right torque.
I hooked up the tail wheel using sash chains and springs, and then adjusted the length of the chains to get about the right amount of tension. I found using zip ties to compress the springs, and to hold the tension on the chain helped to hook everything up.
I then wired up the tail light, and coiled the slack cable into the fairing. This is when I discovered that the rudder bottom fairing can’t be installed with the rudder in final position. After some Vans Airforce research, the advice was to remove the bottom two rudder attach points and swing the rudder sideways and aft to allow the fairing to fit, then reassemble. So at midnight on Saturday I felt like I was starting again, undoing the attach points, taking off one of the sash chains, installing the fairing, then putting it all back together.
Anyway I eventually got it all done and headed home in the early morning hours.
The rudder attach hardware is hard to access Sash chains and springsThe forward edge of the rudder bottom fairing can’t be attached due to tail wheel spring (the white steel tube) interferenceEverything finally in place on the tail
