After giving things a lot of thought, I finally summoned enough resolve to drill some holes in the aircraft skin, and most, where none had existed before. You’ve got to do what you’ve got to do. Antennas, static ports and bulkhead connectors need holes. Now I’ve got them.
Determining the location of antennas is where most of the thought went. I tried to get the transponder blade antenna pretty close to the fuselage centerline – right in the middle as it turned out. Airframe shading and interference between antennas and other equipment are key concerns. The COM 2 antenna is also on the bottom of the fuselage, just behind the rear wing spar carry-through. I tried to keep it as far away as I could from the the transponder antenna and GMU 11 magnetometer. I didn’t get all of the separation distance called for in various installation documents, but what could I do? This is a tiny little airplane — not a King Air. Time will tell if it’s enough. Build on.
All of the antennas are made by Rami and came along as part of the package with my panel, harness and avionics. Some builders have made rather large doublers. For the moment I’m using only the doublers that came with the antennas. I may eventually go beyond those, but for now, everything is in place.
Of the 14 holes that were already in the ELT mounting tray, none were where I wanted them to be. I made 4 more in the tray that allow 4.0 x 10mm rivets, through the fuselage skin and into the tray, without interfering with the plastic case of the ELT itself.
I made an airframe ground lug from a 5/16″ brass bolt and installed it at the location where the KAI called for a 12 AWG avionics ground bus wire to be passed through a grommet in the firewall on it’s way to the negative battery terminal. I’ve decided to have a 10 AWG cable for the avionics ground bus to the lug (inside) and a 4 AWG cable from the same lug, on other side of the firewall, to the battery. I plan to attach a 6 AWG engine [starter] ground cable to the lug as well.
Rubber fuel lines penetrating the firewall through ordinary grommets, as the kit assembly instructions (KAI) call for, didn’t float my boat. I’ve gone with AN6 bulkhead fittings for the fuel supply and return lines. These fittings need smaller holes than the ones pre-punched in the firewall by the factory. I designed and fabricated a doubler out of steel and riveted over the original holes. The fittings are mounted there.
A set of step-drills is absolutely essential for making holes in sheet metal. I’ve got a cheap set but they’ve worked well.
I’ve set M6 rivnuts (with some JB Weld epoxy for good measure) in the fuselage rib, behind the parachute compartment, where the Rotax ECU goes. Getting the 3 large engine wire bundles and connectors in place, given the minimal space remaining with the LRU rack mounted, is going to be super tight. Fingers crossed.
As long as I had rivnuts and JB Weld handy, I decided to rework the Andair Duplex Fuel Selector valve to receive M4 rivnuts and then set them in place. These steps are called out in the KAI.
My factory quick-build fuselage came with not one – but two – static ports in the rear fuselage. However, the factory now says not to use them. They’ve also said they haven’t officially decided where the new location(s) should be either. They think it’s going to be finalized “soon” and anticipate that it’s going to be just in front of the fresh air NACA duct near the front of the fuselage. They sent me a picture and I’ve gone with that location.
The outside air temperature probe found its home in the LH fresh air NACA duct.
Several months ago, I’d taken a look at the landing/taxi light lenses and what it might take to mount them nicely. The LH wing panel was sitting horizontally on a workbench at the time.
About the first thing I noticed was that the mounting holes around the perimeter of the lens did not all correspond to the holes in the wing where the lights and the lens go. The holes lined up (pretty well) with the lens on the outside of the skin, but not when I put the lens in the opening, behind the skin – where it really belongs.
The other thing wasn’t really so much something I noticed, but rather, I realized that I needed to find a better solution for mounting the lens than the factory provided for – sheet metal screws through the skin and into the plexiglass lens. That’s just not going to cut it.
Now I had another classic opportunity for inspirational procrastination. I put the time to good use. It took weeks, but once again – procrastination paid off! The idea of retainer strips with anchor nuts came early. I also found that I’d likely use #4-40 hardware, because metric MK-1000 nut plates are absurdly expensive and challenging to source in the US. I hate mixing hardware standards on this bird, but that’s just how it goes. The blind anchor nuts on retainer strips behind the lens stuck in my head as an obvious solution.
What was not obvious to me at the time, was how to hold the retainers in place so that the lens could be fitted and fastened with the little screws. I made a prototype with a hand-cut strip of 0.020 aluminum and held the anchor nuts with AN426AD-3-3 solid flush rivets. The strip was flimsy and I attempted to hold it against the backside of the lens with – if you can believe it – sewing thread. Once I got the screws started, I’d pull the thread out. I was too unwieldy.
Weeks went by. Then it hit me – the same basic idea, but with 0.5 x 0.025 stainless steel strips, held to the plexiglass lens with little #4 CSK screws and ny-lock locknuts. I had to make new holes in the bottom half of the lens to match the wing, made six retainer strips and mounted them to the lens. Now I have a lens that is easily installable and removable. I’ve come to believe that this is what the factory does for the Sling TSi and I might have seen it if I’d looked at the TSi construction manual. Oh well. I got there. I’ll repeat the fitting and fabrication process for the RH lens assembly.
There are several points in the build where short rivets are required. Sling Aircraft (TAF) has chosen to leave this task as an exercise for the builder, to adapt some from the ordinary ones supplied with the kit. Here I’m shortening 3,2 x 8mm rivets to about 5mm. These will be used to fasten the piano hinge and control horn to the elevator trim tab.
For some steps, I use a small box end wrench and a socket to provide support around the entire head of the rivet, as I drive the mandrel out or back in using a hammer. I use a cutoff-wheel in the Dremel Tool to trim the rivet body.
After nearly two months from the day she left the factory, my Sling 2 quick-build kit has found its way to my shop.
We were on the clock to get everything unloaded and to restore the container to a completely empty and clean condition. Heartfelt thanks to my good friend Charlie, my wife Mary Ann and our nephew Brandon for their indispensable assistance. We extracted the contents of the container with great care and had no issues of any kind. It all went perfectly. Nevertheless, the process certainly called for a good bit of thought and anticipation of the challenges – there are some, to be sure.
Everyone pitched in, including the truck driver. He was very intrigued by the whole affair and happily offered to help. He had no idea what was in the container and his eyes were almost bigger than mine when the seal was broken and the doors opened to reveal an airplane inside! Wow! How cool is that?!
The fuselage, two wing panels and four wooden crates were sequenced out of the container. Initially, the three biggest crates had to go in to the garage. The wings fit perfectly on my handy EAA stands. The fuselage is still perched (and bolted) on the shipping structure, just as it was inside the container. I did loosen the bolts holding the rear [wooden] shipping structure, just prior to extraction from the container. This was to allow some play between the framework and the empennage mounting points on the fuselage, where it had been tightly bolted during shipping. I didn’t want anything on the airframe to get stressed or bent as we moved the unwieldy payload from the container to the shop.
It’s all very exciting. The next steps are to complete parts inventory and build inspections.
I’ve been tracking the progress of my shipping container since it left the factory at Tedderfield Airpark, near Johannesburg, South Africa on December 19 – just hours before the factory closed for a 3 week holiday.
The container found its way aboard the Xin Ri Zhao and sailed from Durban on December 24, bound for Singapore. Upon arrival on January 6, the container transferred to the YM Upsurgence and departed on January 13. The Upsurgence made several port calls in Thailand, Vietnam and China. Finally, on January 26 YM Upsurgence departed Yantian, China. Next stop – Tacoma, Washington USA!
The last position update I was able to find for the ship, before it was out of touch from the free online tracking service was January 30 – abeam South Korea, west of Japan.
During the Pacific crossing – Yang Ming route PN1, I was able to determine – the ship’s ETA in Tacoma was being updated. It looked like it would enter the Strait of Juan de Fuca during daylight hours on February 10. I live just a mile or so from shore and was hopeful I’d be able to see YM Upsurgence sail past.
Up early on the Monday morning of the 10th, I checked my tracker and it was updating the ship’s position again. Just as I’d hoped to see, the ship was reportedly churning along just a few miles west of where I live. We drove ourselves to the near by Ediz Hook in Port Angles, WA and had a perfect view of the strait. There she was – the YM Upsurgence was just where the telemetry said she was.
It was a beautiful morning, sunshine poking through the clouds. The ship passed very close to us and it was exciting to see.
It’s been quite a long journey, but my Sling 2 quick-build should be in my shop very soon. I’m waiting for a call to learn the day.