My Kitfox build

aftCG

Well-known member
Joined
Apr 3, 2018
Messages
400
Location
Tacoma, WA
Finally a section for us defectors!
Early this spring just as 2020 drove into the ditch I swung a deal for a previously started Kitfox 5 with pretty much every 7 modification (or so it seemed. more on that much later). I've been itching to build my own airplane most of my life and was in the market for a project very similar to what I ended up with when I decided "ah screw it, I'll just buy a flying aircraft and go". And no regrets! I've put almost 300 hours on the plane since buying it. It has polished my tailwheel technique considerably, and my short field game in an amazing way. Prior the annual starting recently I was spinning the plane routinely and looking forward to some aerobatic instruction.

I love my Citabria. It has been very reliable, not very expensive to fly and it is always enjoyable. The only thing I don't love about my Citabria is that I can't swing wrenches on it legally. Avionics are so much cheaper on the experimental side. I don't need permission from the King to move my turn coordinator one hole over, or adjust the Kollsman thingy on my alitimeter.

When I ended up with a few bucks in my pocket early in the year it was finally time to act. I watched the ads for a while and one day found a freshly posted ad for the plane I now own. The only trouble was, it was in Ohio and I'm in Washington. Things about my project that I liked was that it came with a complete FWF kit for a Rotax 912 (over $6k), enough Oratex covering to do the job (another $6k+) some high dollar options like aero struts and some lower dollar but still not free options like fiberglass leading edge, extended baggage, Alaskan Bushwheel tail wheel (Scott 3200), single piece windshield and skylight.

With airline travel screeching to a halt in March I took it on faith that the aircraft was represented accurately. The owner sent walk around videos, a complete inventory and disclosed all the known defects. Fortunately he was an honest guy and what arrived undamaged fit the description exactly. In another stroke of luck there was a truck driver/GA pilot at his airport that like to fill his empty back hauls headed west. For less than the cost of airfare for me and my son to Ohio, my Kitfox arrived in front of my hangar in early April.
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Shown above just the way it arrived.

Okay so the known defects:
Were considerable. First, the owner told me he screwed up when he was drilling the wing spars for the strut attach fittings. The front and rear spars on the Kitfox are aluminum tubing, but in the later models there is a long piece of aluminum extrusion that can best be described as the shape of the Batman emergency signal in the sky. When he drilled the holes into that internal extrusion it was too close to one edge, leaving insufficient edge margin for the rivets that follow. The builder purchased new wing spars and extrusions and shortly after that decided he wasn't going to complete the aircraft.
The second defect was that that sexy red powder coating was done in the late 90s, and it was not flawless. I'm assured that powder coating has come a long ways since then. The builder decided he was going to strip the fuselage bare, strip the powder coating and have it all done up fresh. I was in alignment with that idea until I had the plane in my hands about a month

I researched powder coating shops in my area. I learned that while powder coating has come a long ways, environmental restrictions on removing powder coating have made the job difficult and expensive. The only place in my area that would touch an aircraft told me I would have to strip most of it off myself, and they would be able to finish it up and put new powder on for about $1850.

That same previous builder went over the entire fuselage finding where the powder coating was loose, removed it, addressed any surface corrosion and then used two part epoxy primer with a brush. It didn't look pretty but it addressed the biggest flaw of 4130 chrome moly tubing, which is that it will rust quickly if left exposed.

In stripping the fuselage of components the previous owner removed the wood ribs in the vertical fin, destroying them in the process. He also removed a bunch of other components with less than graceful results. I was at a crossroad on how to proceed. Over 95% of the powder coating was just fine. Really nice in fact. The manual also had several areas where it instructs you to grind away the powder coating for bonding, touch up after drilling holes, etc. There was also the issue of some welding which wouldn't be required but would be a really good idea.

The welding
There were two areas on the design of the Kitfox 5 that have been updated on the series 7 that is produced now. One is some triangle gussets that need to be welded to the rudder pedal torque tubes, and the other is a reinforcement where the tail wheel leaf spring attaches by the rudder post. The third area was one I discovered while I was getting familiar with the build process, and that was where one of the two previous owners fabricated the rudder pedal mounting brackets incorrectly - and then drilled matching holes in the fuselage. I would have to have those holes welded up, grind them smooth and then prime/paint/clear coat them.

In the end I decided that I would not strip the powder coating. Along the way I discovered that my local auto body shop sells a two part rattle can epoxy primer from Germany You break an internal seal, shake for 2 minutes and you have 4 days to use it up. Amazing! The same shop can also color match anything from a sample and provide a really nice single part rattle can (also from Germany) and a two part clear coat to go over it, which only lasts a day after you combine the two parts.

I found a guy on Craigslist who could weld 4130. He teaches the A&P program at a community college, does welding on the side and also pilots a King Air 350 for some company. I bought the weld rod he specified from Aircraft Spruce and loaded up my project and took it to his shop. $150 later the welding was done.
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Naively I assumed that would be the last of my priming and painting. I've long since given up on that ideal and I'm super glad I didn't waste my time doing fresh powder coating.

IMG_20200802_083314.jpg
Rudder pedal torque tubes with the added 4130 gussets and freshly painted.
 

aftCG

Well-known member
Joined
Apr 3, 2018
Messages
400
Location
Tacoma, WA
It's funny that I've spent a career designing airplane parts and tooling, including selection of hardware, manufacturing processes and surface coatings - and that I'm WAY more of a hands on, walk out in the shop and talk to the people who do the fabrication than any engineer I know, yet I've never had to perform these tasks. The primary driver of the FAA Experimental catagory is education, and I can vouch that is very accurate.
For example, when I discovered the rudder pedal attach brackets were made incorrectly I ordered new ones from the factory (you can buy them prefabricated now). I guess it's okay to leave them bare but I wanted to protect them. Some of the chemicals that came with my project allowed me to etch and alodine coat these parts. They came out beautifully (which is not what alodine is about), looking almost like I gold anodized them.
IMG_20200611_212247.jpg
Alodine is commonly splotchy, so I was happy with the way these came out. Even though I could have left them bare I want to head off corrosion where possible. I would like to eventually put this plane on floats (another thing I can do without permission from the King).
IMG_20200803_201735.jpg
I'll fast forward slightly so no one falls asleep. Above you see the modified rudder pedals and my newly alodined brackets in place. Those inboard brackets are the base of the brake master cylinder. The outboard bracket (about to be match drilled here) has a dual purpose of being the outer attachment for the rudder pedal torque tube and the outer master cylinder base.
This one had me sweating because it is important that everything be perfect or you can get binding in the rudder pedals. I'm happy to report mine are quite floppy but have no slop.
 

Bob Turner

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Joined
Apr 4, 2018
Messages
1,089
You lucky dude. You will love flying that thing! Better control response than the Decathlon, at least in the pattern (my only experience).

Smart move with the powder coat. I won't use it on anything but rocker covers and steering wheels/control sticks.
 

aftCG

Well-known member
Joined
Apr 3, 2018
Messages
400
Location
Tacoma, WA
You lucky dude. You will love flying that thing! Better control response than the Decathlon, at least in the pattern (my only experience).

Smart move with the powder coat. I won't use it on anything but rocker covers and steering wheels/control sticks.
Thanks. Yes, the rudder is cable operated but roll and pitch are push rod operated. The controls will be very light. I won't drag into too much detail but I swapped the motorcycles in my garage for the fuselage in my hangar and I'm getting WAY more work done on the plane. The tail surfaces are mounted temporarily, I've worked almost all the details of the center console, the seat pan is installed, the baggage compartment is (mostly) installed.

I've just recently installed the pulleys for the rudder cables and the nylon guide tubes for same. Tonight I'll be running the cables from front to back and working out those details.

One thing I'm doing differently from the build manual is a result of owning an old Citabria and of course my day job. Things like the floor boards are intended to be held in with sheet metal screws. Looking at our wing root fairings I would say those don't age that gracefully and can require replacing with larger versions, adding nearby holes and other ugly solutions.
I read where one builder (there are many who did the same) use Tinnerman nuts on the fuselage tabs and machine screws to retain them. Genius. I went with full floating "nut clips" and some nice countersunk washers.
IMG_20200903_185349(1).jpg
Another change I made was where the rudder pedal mounting brackets (the ones I alodined above) mount. The manual has you use washers and nuts. But the firewall folds back under the plane for a ways. If any of you watch Trent Palmer's videos his rudder pedals recently failed (he didn't have the triangle gussets), so he flew to the factory where they pulled the cowl, pried the firewall loose underneath, etc. What BS! I used nutplates from Clickbond, which are held in place with structural adhesive. They each have a goofy looking rubber thing going through them which is a "tool" that locates the nutplate for bonding, supplies clamping pressure and keeps goo out of the threads.
IMG_20200903_181205(1).jpg
Try installing those on your Citabria without permission from the King, even if they are legit aerospace products. This is a close up showing them from the bottom side after bonding but before I came back and touched up the bare metal with 2 part epoxy primer. With this change to the original design I will be able to remove the rudder pedals in about 10 minutes. No need to pull the cowl, upset the firewall or even lay under the plane.

And the next two images will get the reader basically caught up with where I'm at right now.
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I still have to work out the fasteners along the top of those aluminum sidewalls where they meet the center console.

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This past weekend I drilled the holes for the upper attachment of the shoulder belts (see, more touch up!). Those are Hooker harnesses which makes me happy (officially in everything I fly now). I had to cut the slots in the seat pan which is a vague area in the manual but they came out great. I'm about to pull the pan back out, sand it thoroughly and hit it with some two part bed liner.
That's not the best angle to show the cargo area, but it's pretty good size. You have access from over the seatback and also a removable turtle deck from the top of the fuselage. There is a nice triangle piece of cargo bay behind each seat which will be for chucking your headset when you get out.
 

Big Ed

N50247 - '79 Super D
Joined
Jul 20, 2020
Messages
237
Location
Tampa, FL
Fantastic! I am very envious. I have always wanted to build. Unfortunately, life has always conspired to make it woefully impractical. After I retire for good, I will buy an RV-8 kit, lock myself in the garage for a year, and emerge with the perfect cross country machine to park next to my Decathlon.
 

Explorer

Well-known member
Joined
Aug 21, 2020
Messages
75
Location
Pacific NW
aftCG,

Nice! I'm impressed with anyone who takes on a experimental project and see's it through to completion.

The chap from Oregon who flies Medivac with Helo's has a great way of teaching. This is his second Kitfox Build and a very handy fellow. He does it all. Last one I watched was Episode 21. Can't seem to find him this morning on YouTube.

Good Luck!
 

aftCG

Well-known member
Joined
Apr 3, 2018
Messages
400
Location
Tacoma, WA
aftCG,

Nice! I'm impressed with anyone who takes on a experimental project and see's it through to completion.

The chap from Oregon who flies Medivac with Helo's has a great way of teaching. This is his second Kitfox Build and a very handy fellow. He does it all. Last one I watched was Episode 21. Can't seem to find him this morning on YouTube.

Good Luck!
You must be referring to Bryan Bowman, youtube channel "Project Kitfox". I watched his videos before I had my hands on my plane and have gone back to review them as I've caught up to the steps in his early videos. Like me, he's not starting with a factory fresh kit (I'm not even sure he built the yellow one). Great guy, and a great resource.

Good time for an update I guess. Since my previous posts I have installed the rudder cables and run them to the back of the plane. Shown below are the left side cables before the hardware was torqued.
PXL_20201001_040424426.jpg
The left side cables run direct to the rudder and the right side cables splice to the left side back in the tail cone. The book calls them "pilot" and "copilot" but I'll fly this plane much of the time from the right side.
Before I can cut and swage the cables at the rudder I had to stop and do some work. This weekend was spent installing the wood ribs in the vertical fin from top to tail wheel platform. Lots of fitting and gluing which I'm doing in stages so I don't make a mess or bond something in crooked. One of the things that took a while was fabricating some aluminum angles to follow the shape of the lowest rib in the vertical stab where an aluminum access panel goes. Pretty happy with how it came out.
PXL_20201011_204414787.jpg
I will alodine those aluminum pieces and stash them until after the wood has been epoxy varnished. I broke away from the manual where it has you do this drilling and fitting with the rib bonded in place. I preferred to do all the fitting and drilling on the bench so I could get it perfect.
 

Explorer

Well-known member
Joined
Aug 21, 2020
Messages
75
Location
Pacific NW
Question - Did you purposely decide on the KitFox or was it the semi finished kit that caught your attention motivated you?

There's a lot competition out there in the same category. That's the fellow Bryan, he did an early segment on selection - Highlander, Rand's S21, Etc and came up with how he chose the KitFox.

When it comes fabric time. Have you considered using Oratex 6000 System?


Thank you.
 

aftCG

Well-known member
Joined
Apr 3, 2018
Messages
400
Location
Tacoma, WA
Question - Did you purposely decide on the KitFox or was it the semi finished kit that caught your attention motivated you?

There's a lot competition out there in the same category. That's the fellow Bryan, he did an early segment on selection - Highlander, Rand's S21, Etc and came up with how he chose the KitFox.

When it comes fabric time. Have you considered using Oratex 6000 System?


Thank you.
The Kitfox series 5 and newer have been on my short list for quite some time. I love the Rans S20 more than the S21 (aesthetics really, nothing wrong with an aluminum plane) and was considering ordering a new kit. Kitfox being in Idaho means I have less freight charges and (theoretically) better support. My short list also included planes like the RV-6 or 7 which are probably as close to perfection in design as I can think of.

I know most people tell you to "define your mission" and buy for that. My mission is and always will be 2 butts and some bags, with the little wheel in back. Sure the RV would be significantly faster in cruise and still capable of getting in and out of short runways (not river bars necessarily but anything with an airport identifier is fair game). My mission is currently being carried out by my Citabria and it checks all the boxes. It cruises fast enough to make crossing the state or even the country quite possible*. No LongEZ, Lancair or Glassair made my list, though the Glastar did.

What caused me to pull the trigger on this specific Kitfox was the stuff it came with. You asked about Oratex. My kit came with $6k worth of it, though my chemicals are expired. It's white, which I don't love but I'll make it work. Since I'm going with a radial engine I will go after a red on white scheme that might be found on a Monocoupe.

My kit also came with some high dollar options like aero wing struts (about $3500) and the original oval tube type. It came with the complete FWF for Rotax 912 (about $4500), AWB (scott) 3200 tail wheel and an upgraded tail wheel spring. It also came with the fiberglass leading edge called the "Laker Leading Edge", upgraded rudder pedals and some more that escapes me. It has most of the upgrades to make it indistinguishable from the series 7 unless you really know the type well.

*Many people think the Citabria is too slow or too uncomfortable for cross country. I'm a long distance motorcycle rider and I fly warbirds, so the Citabria seems like cheating by comparison.