Well, not how I really planned for things to go based on my last post regarding an AC system. Let me first say that this summer was hot. Hotter than normal and for the few flights I did end up taking, and it was fairly miserable when we were taxing and down low.
One of the big things I’m trying to keep in mind is the comfort of my family. I don’t mind getting a little sweaty as I try to climb to cooler weather, however once my wife and girls start feeling hot and uncomfortable, the will absolutely decide that they don’t want to go flying with me. OR they will only go flying when the weather “perfect”. Not a great situation to be in.
So with this in mind, I did more research, reached out to who I consider the two major vendors of A/C systems, and started to plan how I would proceed. After a lot of consideration, I have decided to purchase the system from Airflow Systems. This is a belt-driven system with an air-scoop on the bottom of the plane for the condenser. After a few conversations with Bill from AirFlow Systems, I decided that I would purchase the system now, while I’m still working on the fuselage and have full access to the floors to help plan cable routing.
Looking forward to getting the AC kit so I can get a better idea of installation, hose routing, and other items. I know there are lots of good blog posts out the and photos from others, but sometimes having the items in hand make it easier for me to fully understand how it all goes together.
So the title of this section is long, as it should be. There is a lot going on in this section. Basically building up all the parts between the wing spar and the firewall and then attaching the mid-fuse to the fwd fuse.
First few steps in this chapter are building the FWD seat rails and the attach angle to the tunnel. I believe there is a slight difference between the F-1043C angle and what is depicted in the plans (plans show extra holes that aren’t in the actual part). Just ignore this and keep building. (At least that’s what I did!) Beyond that, this is an easy cleco parts per plans, final drill, countersink where needed, (prime if you want), then assemble.
The only suggestion I can provide at this stage is rivet the ribs together before you install the nutplates. I didn’t and it was a little more difficult to set the rivets to hold the ribs together. Ended up having to use a modified rivet set that was shaved down to get access to the factory head as the nutplates were in the way.
With the seat rail ribs assembled, you can then begin to assemble the jigsaw that is the FWD Fuselage Bulkhead sub-assembly. Lots of pieces bolted together with assorted nutplates and clecos. Honestly this was a little fun trying to put it together. Presented a little bit more of a mental on how everything goes together. Another item to note, the plans don’t tell you to do it but final drill all the screw holes on the F-1043D cover plate. The pre-punched holes are too small for the AN515-8R8 screws and they won’t thread in correctly.
I will say cutting the column control mount bracket was slightly scary. I always feel like I have to be so precise with things like this and I really won’t know if I really messed it up for quite a while. Fingers crossed that I was “close enough”.
Other than that, not too hard, just a lot of spacial thinking to get everything together. After building one side, the other goes together much faster!
Looking ahead I really need to get my mid-fuse bottom skin riveted on soon as that needs to be done before I try to attach it to the FWD fuse. Hopefully I can get that done somewhat soon. Also things are getting REALLY crowded in my garage now. I have been thinking I need to move my wings somewhere else, but need to work out the logistics.
Next on the list was building the firewall (Section 27). After pulling the firewall out of it’s protective shell and locating all the needed parts, I was able to start clecoing everything in place. I found there was some finishing work that needed to be done to get all the firewall braces to fit together properly. Nothing major, but just a little different than most of the other areas so far. Maybe that was to make sure that you had a pretty tight fit between components?
One thing I’ll note that is ever called out in the plans. The stainless steel firewall is SHARP. I really tried to be careful around it but did end up with a few fairly deep cuts on my hands. Worst papercut ever!
Once all the braces were final drilled, I moved onto the tunnel. Nothing really difficult here either beyond measuring where to drill for the SCAT tube support. Cleco the remaining parts together, final drill then deburr everything and prime.
With all the parts primed, it was time to deburr the firewall itself and dimple. A few things I’ll go ahead and call out.
As called out on Page 27-5, two nutplates are installed on the engine side of the firewall. This isn’t mentioned in the steps but dimple correctly for these nutplates.
I went ahead and dimpled ALL the holes on the firewall as I was unsure if I should or not. Were I to do this again, I would not dimple the holes under the F1001-C (bottom of the firewall) as a squeezer could get there later. Can’t comment on Upper Fuse ribs yet.
Riveting the braces onto the firewall skin was straightforward. Just don’t rivet the area where the triangle brace goes or you will need to drill that out later. I ended up backriveting most of this with only a few minor issues. I supported the firewall on scraps of plywood so I didn’t bend any of the flanges.
The only other “mistake” I made was when I was riveting the WD-1004 brace to the tunnel skin. I read the note, but still put the rivets in backwards. Drilled them out and put them in correctly just in case. Honestly it was easier to rivet following the directions (shop head on the WD-1004 side)
At this point my mid-fuse bottom skin is still not riveted together, just waiting to get someone over to help me set these rivets. Maybe I could back-rivet these on the bench, but getting a helping hand seems like a better idea.
So slightly out of order, but figured I would provide a quick update on my fuel tanks. I found myself with some spare time to work on the airplane due to my wife and daughters taking a trip to visit my mother in law. This is great except for one minor detail, I basically ran out of things I can work on by myself and need a second set of hands. Local buddies were are also unavailable so time to get creative.
Decided to bring the fuel tanks back from our storage locker and finally pressure test them. Going in I already knew I would need to cut a hole in my right tank to replace a rivet that somehow wasn’t fully set?!? Before I drilled it out I wanted to verify there were no other areas that needed attention (leaks).
With the fuel lines (supply and return) capped, and a balloon on the vent line, I used the fuel drain line to blow into the tank and slightly inflate it. (Just a few breaths to put a little pressure in the tank, not enough to inflate the balloon). Then its on to spraying soapy water all over the tank. On the first try, I got a leak around the fuel cap and the threads of the fuel supply and return. Tightened the caps on the fuel lines, and tightened the screw on the fuel cap. Re-spray and no leaks. Ok, so a tank in good shape. Now for the difficult part (emotionally that is).
Tape role makes a good template
Rough cut the opening with a Dremel
File all the rough edges.
Line up the cover and match drill all the holes.
Don’t forget to remove the primer where proseal needs to go.
All Done!
With the hole cut in the tank and the edges deburred, I was able to get into the tank to remove the proseal from behind the “bad” rivet and drill it out. Note: removing the proseal from inside the tank SUCKS! Make sure all rivets are properly set to avoid this torture!
Once the area when the rivet needed to be installed was cleaned, and all the dust and debris was removed from inside the tank, I was barely able to install a replacement rivet. Honestly I almost gave up and was looking for an appropriate flush blind rivet, but in the end I was successfull in installing the new rivet (pending leak test).
With the rivet installed, I added a bunch of proseal to the area to prevent any leaks in this area, followed by installing the access hole cover. No way this patch will leak due to the large overlapping surface and overkill number of blind rivets. Now I’m just waiting for the proseal to cure before I attempt a pressure test. The other tank was perfect, so I already mounted it to the left wing with just a few bolts / screws. I’ll get more photos of the tanks mounted in a future update.
Next week, I’ll be in Chesapeake VA attending the RV Fiberglass class to practice making the windshield layup so don’t expect any real updates for a few weeks.
Now that I’m basically done with the wings, I can go back to working on the fuse. Section 26 – Mid Fuse Ribs and Bottom Skins will be creating the back half of the fuselage floor. As this will take up some significant space, I wanted to make sure I finished up the left over little stuff on the wings.
Before I even started, I read through the chapter to ensure I understood the sequencing. I quickly realized that I have to do a few steps, prime a few parts, rivet those parts together, then do the next few steps. This repeats throughout the chapter vs most other sections where I can prime and rivet everything at the end. Lots of little primer sessions in my future!
First few steps, build the Inner and Outer seat rib subassemblies. Nothing new with these parts. Only thing I should have done was to fabricate and include the flap motor mount parts when I primed the subassemblies.
Next, I start pulling the parts for the rear seat ribs and fabricating the seat belt brackets for them. Before I cleco these ribs to the bulkhead, I need to rivet the previous brackets to together. TIP: Make sure you flute the outer most ribs to match the bottom skin. (F-1015L/R and F-1018L/R). These are really the only ribs that need to be fluted, and as others have found it’s quite difficult to flute them once they are riveted together.
Again, nothing hard, just cleco, match drill, deburr, prime, and reassemble. About now, things are starting to get big so I ended up getting one of those “cheap” work platforms from the big box stores. Another option would be to stack some 2/4’s on the ground as a platform as the bottom skin needs to hang down past the forward bulkhead a bit.
Only other “gotcha” or oops I had was that I didn’t check the alignment of the F-1018R rib with the fuselage bulkhead assembly and allowed the rib to be trapped inside the flange of the bulkhead assembly. It should have been on the outside of the bulkhead and I had already started to rivet things together. Not a major problem, but I’m not a fan of double work. Drilled out enough rivets to allow me to move the parts into the correct position. From there, all is great and I’m able to build on :).
Lastly I start to cleco the skins onto the ribs and bulkheads. This was really cool to see and starts to make me worried about space issues in my garage. For now I’m rolling with the punches, but things may get interesting in the next few sections. With such a large part, I decide that I’m going to mark every hole I drill to make sure I don’t miss anything. Makes match drilling go a little slower, but I’m ok with that.
UPDATE: 4/7/2020 – One thing not fully covered in the plans is where to put the MFG heads vs the Shop heads in this section. Only when I went to install the rear seat floor pans did I realize there may be a recommended method. Where possible, put the round MFG head on the passenger visible side. It not only looks better, but also makes it easier to install the floor later on.
NOTE: While not called out in the plans, I would HIGHLY recommend that you dimple the F-1015B and F-1015A #40 holes now to allow the side skins to sit flush once they are dimpled. While it can be done later, it’s a pain in the rump. See Plans page 29-15 and 29-17 for rivet callouts.
