109JB stumbled on another Kitfox IV project

[109JB]

I'd heard from other folks that live near me about a Kitfox that lived on a farm about 5 miles from my house. It had not flown for about 5 years from what I heard. Well, about 3 weeks ago we had some bad storms roll through the area. My weather station recorded a peak gust of 68 mph and while the storm was going on I consistently saw it reporting 50+. We lost a huge oak tree in our front yard, and it turns out the shed the Kitfox was in partially collapsed on it. A friend of mine was in the group of guys that helped the farmer pick the roof of the shed up and get his stuff out. That friend told me about the kitfox and I decided to go talk to the guy. Well, one thing led to another and I bought the airplane.

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Here is the list of what I saw needing repair.

One prop blade chipped (Will replace all 3
A bit of upper forward cowl damage
Bent aft fuselage
Bent rudder and vertical tail
Left forward wing strut tube bent
Tip rib on left wing cracked
Left fiberglass wingtip needs repair
Windshield and cabin root ribs cracked


I already started on the aft fuselage repair by cutting out a section of the top fabric and peeling the side fabric off the longerons. Then I used my straightening tool to pull the upper longerons back closer to shape. Unlike the other 2 fuselages I have straightened, this one will require cutting out a section of one longeron and welding in a splice. That one is the S-shaped one in the pictures below. I still have some tweaking to do of the other tubes in that area but they should be okay.

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The shed roof landed on the rudder and pretty much mangled it and that bent the fin slightly to one side. I could straighten the fin, but am going to take the opportunity to enlarge it and make a larger rudder too because this is an early Kitfox 4 with the smaller tail. It is a 1050 gross weight model.

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The airplane had a custom trailer as shown in the picture above, but I didn't buy that. I told him I would put it on the forums to see if anyone was interested in buying it. It was too high priced for me at $3000 but maybe someone else doesn't think so. It is well built and works well. The way it is built, without modification, it would only work for standard gear like the Kitfox 4 came with. It is in Morris, IL, if anyone is interested.

[Eric Page]

I'm glad to hear you're giving it a second chance. You better update your signature to add a fifth airplane!

[109JB]

So while working on this project, I discovered that the static line for the instruments are just open to the back side of the instrument panel. I know many do this, but since I have the aft end fabric off of the fuselage I was thinking this is a good time to add static ports to the side of the fuselage. My preference would be a dual tube pitot static setup on the wing but am not going there on this one. I don't know if this airplane will ever get a transponder but if it does, I'm wondering about transponder checks. So, a few questions:



how do those with cabin static sources get your transponder encoder checked?
Any pushback from the shop on using cabin air for transponder encoder.
If I do a fuselage mounted static, where is the location recommended by Kitfox?


I did find this picture online showing one builders location. Is this where kitfox say to put it?


Thanks.

[jrthomas]

I installed the dual static ports just like those pictured per the Kitfox manual. They work!

[Delta Whisky]

John - regarding the transponder test: if you are talking about the 91.413 test, the transponder connection to a static source isn't an issue. (It refers the reader to FAR 43, appendix F which can be done on a bench.) If you are referring to 91.411 - well that is a different issue BUT my experience is that the bigger issue is finding maintenance personnel that agree only a 91.413 is required. 91.411 is required for IFR flight and adds appendix E of FAR 43 which is where the altitude accuracy comes in. I've experienced several test stations and personnel that think compliance to 91.411 test is required. Others say not it ain't!! Find one of them. (Disregard all of the preceding if you fly IFR.)

BTW - discussion for another day is: if you have ADS-b, why isn't an inflight test report sufficient (in lieu of a 91.413 test)?

[efwd]

Mine is open to the cabin. I have an avionics shop do the verification. No problems.

[109JB]

Thanks for the responses on the static port.

I got a bit more done yesterday but momma had a honey-do list. I did have time to get a friend over to get the wings off and also got some patching done on the wings and stab.

[109JB]

Got more done this week. Tubing finally arrived and I got the longerons fixed and side covering on.

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Also had a crack at repairing the busted upper cowl. To fix this I simply used a cutting wheel on a dremel to open the cracks and allow the pieces to be pulled back into position. From there I used bits of tongue depressors and hot melt glue on the outside to hold the cowl in proper position. Then a right angle air grinder with roll-loc disks to grind down to bare clean glass and layed up glass on the inside. Used mostly 2 layers, but sometimes more depending on the area. Amazingly a trial fit shows it worked.
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[109JB]

Well, I met my goal of having fabric on the fuselage by this past weekend. The fabric was attached using Ekobond and I'm using the latex paint method on the patches. I decided to do this after checking a spot of old fabric by cleaning it with acetone. There is obvious darkening of the paint over the years so even though I know the polyfiber color, new paint would not match well. Anyway, I've now got the weave filled and starting on color. Before anyone says anything the color on it in the picture below is too dark. This was a computer color match but doesn't match. Since I'm using latex I went to the paint store and rather than refund my money, I got them to sell me another quart at 1/2 price that was tinted too light. I've been experimenting with different ratios of dark and light paint and am pretty close to a perfect match using 2/3 light and 1/3 dark color. I'll get the exact ratio I need after a few more tries. In the meantime the dark paint is on as a base since yellow is such a pain to cover.

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I also moved on to enlarging the vertical tail to match the size of later model 4s. I didn't know the fin leading edge tube was 0.049 wall thickness, so I had to order a new piece. Rudder was enlarged and instead of rounded corners I went with squared off corners.

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[109JB]

Tail modifications are done and fabric and tapes applied.

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[109JB]

Aft fuselage damage done. Paint looks like a perfect match in the shop. Tomorrow I'll roll it outside and see how good it is. Next will be re-installing the root ribs on the cabin and making a windshield. At that point if the wings were on it could be considered airworthy but I have a few more things to finish, Mainly finishing fiberglassing the left wingtip damage, the front upper cowl and painting those. I also have to replace the seals in the engine, but it is getting there.

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[DesertFox4]

Nice work John. Good as new! 👍

[109JB]

I'm very motivated on this project and am in "don't think too hard., Just do it" mode.


Got more done today.

Got a windshield made and installed today
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Got the patches on the horizontal stab painted last night
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Installed the tail surfaces for the final time
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Also started the fabric that closes out the fuselage to the root ribs.
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I also installed the tailwheel and redid the springs because I didn't like how the previous owner did them. Once I paint the root rib closeouts the doors will go back on and it will be essentially fixed except for finishing the cowl repair and the engine stuff. Later tonight I'm going to pop the cylinder head off to make sure it is still standard bore and will order the top end kit for the 582.

[109JB]

Rolled the fuselage outside to clean the shop and also check the paint match in sunlight. Came out very close. Just about perfect. About another week of work and this one will be back in the air.

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[alexM]

BTW - discussion for another day is: if you have ADS-b, why isn't an inflight test report sufficient (in lieu of a 91.413 test)?

Because your ADS-B "out" is using your mode C altitude encoder, and not GPS? The question mark is because I'm only making a partially educated guess. I installed Stratus ESGi transponders in two different planes to meet the Jan 2020 deadline. I remember being surprised that they still needed an altitude encoder, and also that encoders weren't just built into every transponder since the 1980s.

As an end user of those transponders I can recall that they display pressure altitude if you want (and I did).

[109JB]

Wrong. ADS-B out transmits both pressure altitude from your encoder AND GPS altitude. https://www.faa.gov/nextgen/equipadsb/resources/faq/#q36

Also, encoders aren't built in because some might want to use an encoding altimeter or the altitude source from their EFIS. Both can provide the altitude required for mode C and it will math the altimeter unless something goes wrong.

[Kitfox Pilot]

John I am very much enjoying your work on this rebuild. Very nice work. What kind of a seal is that between the windshield and the cowling?

[109JB]

I'm not really sure exactly as the previous owner installed that seal. A little searching on mcmaster carr and it appears it is an edge type wiper seal. I think it is about 3/4" overall width but will get you a close up picture and a measurement next time I'm out there.

https://www.mcmaster.com/edge-seals/edge-seal-style~wiper/

[109JB]

Getting close. Fuselage is pretty much done. Had to pull the engine and de-carbon the pistons and also split the case to replace the crank seals but I got it back together, back on the airplane and fired up that mighty Rotax 582 today. New flaperons coming this week. Once those are on it is ready to go.


https://youtu.be/H1ZeBLk6j9A

[109JB]

Got the wings back on. I'm now just waiting for new carb jets and I should be ready to get it to the airport for its first flight in many years.

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[DesertFox4]

Getting close now John. Good luck with first flight. She looks good.

[109JB]

She is at the airport and I finished all of the final tasks before flight. One of those tasks was re-weighing the airplane. CG is good and empty weight is at 553 pounds. Very happy with that number. It actually lost a few pounds which I attribute to the Lithium battery. Not much else changed during the rebuild that would affect weight. Unfortunately the first flight is going to have to wait until nexy week as I am getting sent out of town for work tomorrow, and we could get 10 inches of snow Saturday. A little bummed that I'll have to wait.

[109JB]

Weather finally cooperated and I got a flight in today. She flew very well and it was a smooth day to do this first flight after the rebuild. No pictures or video though. The Insta 360 camera somehow didn't charge or the battery is bad. Anyway, it flew well only a couple squawks to take care of.

1. Need anti-slip tape on the rudder pedals
2. Need to adjust brake pedal angle
3. Engine needs leaner idle jets and richer main jets
4. Gotta plug the big air leak where the landing gear bungees are.

Like I said though, the airplane flew beautifully so I am a happy camper.

[DesertFox4]

Congrats John. Happy all your efforts culminated in a great flying Kitfox.😀👍

[109JB]

I've been flying as regular as I can but its hard when it gets dark 30 minutes after work ends leaving only the weekends and hoping for decent weather. I think I have all of the minor bugs worked out except I think I'll be getting the Matco intensifier kit for the brake master cylinders since I can't hold a full throttle run-up. Also turned out that what I thought could be a high EGT problem was the gauge reading wrong. A new dual digital EGT shows it is running perfect. Everything except for the somewhat weak brakes is good and it is flying really well. I was pleasantly surprised that it has required no adjustments for rolling or yawing tendencies.

I also finally got my camera working and got a video of today's flight. Previously my camera refused to record more than about 2 minute because of the cold weather and I finally had to run a wire with a 5v USB converter on the end out the strut to the camera. Here are the last 2 landings of today's flight . Both videos are essentially the same but the first is a "normal" video whereas the 2nd one is a 360 degree video. If you watch the 360 degree video on your phone you can move your phone around to pan the view.


https://youtu.be/1VMHIU0TCDQ


https://youtu.be/20woFqwNJrI

[DesertFox4]

Nice work John. She flies great. Nice landings by the way. Enjoy every flight. Hopefully nice flying weather will arrive soon.

[109JB]

Nice work John. She flies great. Nice landings by the way. Enjoy every flight. Hopefully nice flying weather will arrive soon.

Thanks. It is flying really good. I blame the smooth air yesterday for the landings. My normal usually have a little more plop to them.

[109JB]

Got some pictures of the airplane out in the sunshine yesterday.

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[Dave S]

Beautiful covering and paint! Like the interior also!

[Kitfox Pilot]

She really looks good in the sun!
I like the way you closed out from the seats up to the top. I may copy that to slow drafts during winter flying.
Harlan

[Geek]

She really looks good in the sun!
I like the way you closed out from the seats up to the top. I may copy that to slow drafts during winter flying.
Harlan

How are you going to reach your cooler of (fill in the blank here) that's back in the storage sack if you close it off Harlan? You have to think of these things!!!

Geek

[109JB]

Got a few pictures while out flying today.

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[MikeMarkota]

Great work! Mind if I ask what kinda climb / cruise speeds you get with the 582 ?

[109JB]

Great work! Mind if I ask what kinda climb / cruise speeds you get with the 582 ?

Hi Mike,

I happened to be out flying this afternoon if I remember right the AWOS was reporting about 1800 ft density altitude. With full fuel in the header (10 gallons) and me on board (225 lb), I was getting about 1000 ft/min at 60-65 mph indicated up to 500 ft AGL.

As for cruise I can push it up to about 85 or 90 mph based on GPS around 6000 rpm. Airspeed indicator is showing 100+ at that speed but it isn't right especially at higher speeds due to static port open to the cabin. At lower speeds the airspeed indicator seems pretty close like approach speed down to stall it isn't too far off. At stall, the airspeed matches the GPS real close. , When just bombing around I throttle back to about 5500 rpm and suppose I lose about 10 mph but haven't really been paying attention too close. On this airplane I've put about 20 hours on since the repairs and on my list of to dos is to put a proper static port on and to do some performance testing where I actually record things.

[MikeMarkota]

Wow! That's great performance - I might put my GSC prop back on and see if I can get numbers like that again! I've been like 600 ish ft/min at similar weights and speeds on hot days, but I have an IVO prop. My air speed indicator gets pretty optimistic over 85 mph too, but is dead nuts on under 75 mph.

[109JB]

Went flying again today, 2100 ft density altitude today. Didn't do much but did a 2-way east-west run with reported winds straight out of the east.

I have to mention I have 2 tachometers, a knock-off tiny-tach digital with the sense wire wrapped around a spark plug wire, and a Rotax analog gauge reading off of the tach wire from the stator. They do not read the same and I have not had the time to use my optical tach on it to determine which is right. The tiny tach reads about 400 rpm higher at any meaningful cruise/takeoff RPM.

At 5500 on the Rotax tach (5900 tiny-tach), I got 94 mph GPS heading due west and 73 mph heading east so my airspeed was right at 84 mph. The airspeed indicator read about 95 mph, so is about 10 mph optimistic at that speed.

I went back to the airport to practice hard surface x-wind TOLs (runway 36), and did about a half dozen. Today I didn't feel like the real steep 60 mph indicated climb attitude so I opted for 70 mph climb out. The sustained climb rate to pattern altitude was consistently right around 800 fpm according to the VSI. I haven't done timed climbs but it seems about right. It was just me (225 lbs) and about 1/2 fuel in the 10gallon header tank.

[109JB]

FAA finally came through with the registration so I am going to sell this Kitfox. It is a kitfox 3 fuselage with kitfox 4 wings and mixer assembly, so essentially a Kitfox 4 1050 gross weight. Has 500 lb useful load,, one 10 gallon header and one 6 gallon wing tank. When I did the rebuild I enlarged the vertical tail and rudder to the same size as the kitfox 4 1200. The airplane flies great and is put about 30 hours on it since the rebuild which this thread details. Has a Rotax 582 that was disassembled, crank checked , outer crank seals replaced, decarboned, and tuned really well. I will put up a pdf of details later, but wanted to get this out now. Asking $29,000

[109JB]

Price reduced to $27,000