Backseat floor skin mod

Time: 0.5 hrs

I decided to modify the backseat floor skin (CF-SKN-021) where is sits under the rear panel of the center console. The holes didn’t line up and I don’t think they were all that necessary since the backseat floor skin sits under the panel and there are plenty of screws holding it to the center section of the floor.


The piece on the right is the backseat floor skin and the other piece is the rear panel of the center console. The holes are a little off.



I need up just cutting them off completely and left a tab that will fit behind the rear panel.


Also contemplated on how to get these side floor pieces to fit right. I know that the flag is supposed to fit on the outside of the main support piece, but mine just won’t fit that way.


If I fit it in front of the support then the top holes don’t line up with the holes in the seat rails. But in all the photos I’ve seen and the Sling 4 at KTOA this piece is suppose to fit in front.


If I put it on the inside then all fits great and the top holes also line up with the seat rail. So it looks like I need to move the bend about 1/8 to 1/4″… Hmmm. Or I just leave it this way.

Misc Work

Time: 1.25 hrs

Things done today:

  • Ran wiring for control sticks
  • Installed rest of edge grommet on rear seat bottom section

Ran #22 for AP disconnect, #20 Ground, #22 PTT, and a 4 wire #22 for elevator trim and flap control. I did short runs out from the pilot and co-pilot sticks to the center console area and then a long run from there to the instrument panel. I’ll install a connector to tie them together. The AP disconnect, elevator trim, flap control, and ground will all be tied into one cable run each back to the VPX. The PTT wiring is separate for the co-pilot and pilot, I also color coded (grey/green for pilot, grey/blue for co-pilot)  them so I don’t mix them up later. Next, I need to experiment with printing the heat shrink tubing from my labeler.

Misc Work

Time: 2 hrs

Things done today:

  • Installed rivnuts in center rear floor panel
  • Riveted elevator AP servo mounts
  • Riveted flap actuator mount
  • Removed soundproofing from hole of transponder antenna
  • Contemplated location of GPS antennas



I had thought I saw some photos of rivnuts installed here instead of riving the center floor panel in place. Putting in rivnuts allows the center panel to be removable. I asked the factory and they said to install M3 rivnuts (I kind of though M4 would work better, but OK).



I’m committing to using a monopole antenna. I checked with the factory and they concurred that this would be the “best” route to take. If I do have issues using the monopole with ADS-B in/out then I think I have devised a plan so that I can still use this location. I would probably have to go with the more expensive C105-7 (I think that’s the model) transponder antenna  so that I could mount it with four screws and rivnuts. In any case I had to remove the soundproofing from this area. Fortunately I only put 1 layer in the middle section, but it still was a painful process to remove it. The foam part was easy it’s the sticky tape that was difficult. I ended up using Goo-gone and some Q-tips to remove the sickness. It also seemed to weaken the plastic part of the tape they used so that eventually came off as well. After all the stickiness was gone I used a small piece of scotch brite to clean the area.



So after some research it turns out you only need at least 12″ of separation for the GPS antennas. TAF installs the GPS under the cowling (where is says “GPS1” on the right side). So I’m thinking I can probably make a mount and install GPS2 on the other side… maybe move GPS1 over a bit as well. It would keep the cabling nice an short.


Misc work

Time: 2 hrs

Still waiting for parts. Did a few random things today:

  • Riveted gear uprights (CF-ANG-006 L and CF-ANG-007 L) to gear upright joining channel (CF-CHL-008 ). Missing CF-ANG-006 R, so can’t do the other side yet.
  • Countersunk a of few the inside holes in the gear upright joining channel.
  • Put a few rivets in the seat rails that I thought were safe to do
  • Reamed out seat rail adjustment holes to 8 mm (thanks Craig for posting)
  • Ran AP disconnect wire to AP Servo locations


All seat rail adjustment holes have been reamed out to 8mm. After looking at how the pins from the seat adjustment mechanism would fit in these holes I knew that they needed to be reamed out a bit… then the next day I see a post on Craig’s site about reaming the holes to 8mm. I also riveted a few things on the seat rails like the flanges that  the center console skins screw into and a few rivets on the top that seem to be OK to do.



Ordered a bunch of cable from Prowire USA (, so much cheaper then Aircraft Spruce. This is mainly unshielded cabling for power and grounds, but they also carry some shielded Tefzel. The yellow wiring will be used for runs to any lighting, the orange is for equipment that will be fed power from the backup battery system (TCW IBBS). I added the 22 gauge wire to the bundles I already ran to the AP servos so those runs should be done now… unless I forgot something.

Wire Run List


Having been an audio engineer I was familiar with the idea of creating wire run list for all the cable runs in a studio (and there are many). So I thought I’d do something similar for the Sling build. I’m posting this just in case someone might find this useful. I’m also hoping it will help me estimate the quanity of all the different wiring that I need. I’m just posting a screen shot of what I did. If you’re interested let me know and I can send you a copy of the file. Having this in a spread sheet is pretty cool actually because if you sort the columns you can identify all the wires going to a device. There is an issue where if you’re not consistent with saying something is always the source then you need to sort by “Location A” and also by “Location B” to find all the connections to/from a device. I also was able to add some calculations to add all the different types of cabling to give me a total of all that type of wire I need, also there are calculations that count usage (if an “X” is placed under the “Installed”column for a run). By using the calculations I can roughly see what wiring I still need (in red) or if I have extra. As more wiring is purchased I can just increment the purchased column in the Inventory table.


Search for things to do

Time: 2 hr

Did some random stuff on the plane in an attempt to keep busy while I wait for my parts.

Things done today:

  • Ran wiring for AP servos
  • Drilled out two holes for battery reinforcing bracket
  • Notched top of battery reinforcing bracket
  • Riveted battery reinforcing bracket to firewall
  • Installed a few rivnuts in firewall
  • Riveted top front rib
  • Put a few rivets in the seat rails
  • Installed M3 screws into throttle assembly
  • Installed edge grommet on rear bottom seat section


I did a rough run  of the wires to the roll and pitch servos (which I don’t have yet… Hey Christmas is coming so I can hope). I will daisy chain the power, ground, AP disconnect, and CAN bus from the roll servo over to the pitch servo. The roll servo also gets an extra 22-2 for RS-232 to the GMA307 AP Controller. The pitch servo will eventually have an additional (2) 22-2 runs for the pitch trim motor. The pitch servo is also the end of the CAN bus so will have to jumper some pins on the connector when I wire that up. I also need to install some adel clamps or the like to keep the cables in place.


I figured it was safe to install the battery reinforcing bracket. There were two holes that got covered by the top firewall reinforcing channel so I needed to drill those out. Also the bracket overlap the top bracket (grey bracket in photo) so I made a small notch in the battery bracket so it sits flat on the firewall.

I also received the M3 socket cap screws from BoltDepot today so I loosely installed those for the throttle stops in where I think they need to go. I added some heat shrink on the screws just so the throttle lever wasn’t hitting the threads of the screw. It took some experimenting, but what I ended up doing was to cut a piece of heat shrink and put it on the smooth end of a 7/64″ drill bit then heated it to lately shrink to that size. I then removed the heat shrink from the bit and slid it over the screw threads when installing the screw. I probably could have just shrank it right on the screw after it was inserted, but I was worried that for one the heat gun would bubble the primer and two the heat shrink would stick to the screw making it very difficult to remove the screw if I needed.


Installed some edge grommet to the seat belt holes in the rear seat bottom section. The paint came out pretty good too… not too bad for a table in the back yard with a can of rustoleum from HD.

More Throttle Lever

Time: 1 hr

I had primed the throttle mounting brackets a few days ago so I assembled the throttle as much as I could. I had to drill some holes that were missing on the one bracket and added another hole that was missing on both. I don’t think all holes are necessary as per the manual you don’t end up using most of them since they are just to stop the throttle from moving past a certain point. I also had to order the M3 x 20mm screws (missing from my kit) that are inserted in the holes that serves as a throttle stop. I’m thinking I can use some nylon hose to cover the part of the threads that the throttle lever will hit.  I also installed the 6 M3 rivnuts on the top for mounting to the cover panel.

So besides installing the throttle stop screws once they arrive I’m pretty much at a stand still with the fuselage until I get my missing/incorrect/damaged parts replaced. So probably no updates for a while (really hoping it’s not long).


Throttle assembly all assembled. Had to drill out a few holes on the top portion of the bracket. These are throttle stop locations where a M3 screw is inserted through the assembly. The other bracket (under the one shown) didn’t have any of the back holes. I drilled out the lower four since from the manual is seems like the second from the end is used. In the front part I drilled the single hole that is above the two. The manual says to use this hole (which I guesstimated its location), however after some looking at the throttle it may be better to use the forward most hole (in the lower row) since you don’t really get much throttle movement past the boost stop (and we want a lot of turbo boost 🙂 ). This is the 115% throttle position that is used on take off climb out for up to 5 minutes. You can see in the photo where the throttle stops unless the small lever in the front is use to move past the stop into the boost area.