First Wing Attached
(Oct 11 & 12, 2025) I attached the starboard wing this past weekend, a big step towards transforming this air vehicle from a missile into an airplane. Given just how much care went into building the wings & fuselage, and the whole process of moving them to the airport, I was nervous and excited to finally complete this step.
First, I pinned out the electrical connections at the wing root. I had left these wires loose until I was sure how much wire to leave for service; as it turns out, this part of the wing sits really close to the fuselage skin, so not much service loop was needed, therefore I trimmed the wires back a lot. There’s no space to access these wires/connectors once the wing is attached, so it’s important to get the wiring correct the first time.
I roughly installed the fuel lines, but there are fairly generous access portals on the bottom of the wing, so I’ll complete these once I determine the optimal lengths for the hoses. I have feed/boost pumps installed in this compartment on each wing, so there are a few more components here than standard.
I used an adjustable lift table from Harbor Freight to set the inboard height of the wing, and a fixed height table with some pads & foam blocks to set the angle (dihedral) of the wing from the wingtip edge.
It was a challenge to install the wing. During the fuselage build I put wood blocks into the slots while attaching the skins around the wing spar to ensure the wing tabs would fit. Despite this precaution, it still took a great deal of effort to maneuver the tab into the slot. The manual suggests using warm soapy water, but that didn’t help much, so I applied a little bit of grease to the tab. The grease definitely helped, and I was able to push/rock from the wing tip to align properly the wing into the slot and line up the bolt holes. Big thanks to my hangar mate Steve (he’s building a Zenith 750 Super Duty) who helped me get the wing in place.
Securing the wing with the AN7 bolts was an entirely difficult experience. The KAI advises not to drill the holes in either the wing tab or the center fuselage spar carry-thru, but both of these parts are made up of multiple laminations of aluminum plates. Maybe these holes were drilled / aligned perfectly when they were built at the factory, but after years of sitting in my garage plus all the jostle of their journeys, these holes were no longer perfect and were nearly impossible to put a bolt through, even before attaching the wing. After getting 3 of the 8 total bolts installed with a heck of a lot of force (which definitely shaved some metal in the process), I was unable to get any of the remaining 5 even started in the holes. Therefore, I used a 7/16″ chucking reamer to finish the remaining holes to proper roundness and diameter, after which I was able to get the bolts through, though it still required considerable force with a mallet and air hammer.
One particular struggle was getting the the lower bolts installed. The KAI shows the head of the bolt going through the front side, but due to the sidewalls and the floor panel not shown above, it’s difficult to line up the bolts square to the hole — and as tight as the holes are, the bolt won’t budge if they’re not square to the hole. As you can see in the next picture, the floor panel interferes with the bolt heads, so I had to slam the bolts in at a slight angle, which chewed up the rear edge of the floor panel. For the lower outermost bolt, it’s even more difficult/impossible since the interior skins and one of the longerons severely obscure the hole. I chose to install this bolt in the reverse direction instead (similar to the outermost bolt on the top row), which was much easier since there is ample space on the rear side of the spar box. Even so, it was still difficult to secure the locknut since there is no room to get a socket onto the nut; I had to use a open ended wrench at an angle. I suppose this step would be easier to accomplish if the interior skins were not installed yet.
On Sunday, I was able to get the remaining 5 bolts attached so that I could remove the support from under the wing. To my great delight, the wing didn’t fall off! Also I was relieved that having a single wing installed didn’t cause the airplane to tip.
