Just bought a Kitfox IV

[109JB]

So yesterday I bought this Kitfox IV


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Unfortunately I discovered that transporting a Kitfox on a 14,000 pound capacity utility trailer isn't a good idea.

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So today instead of flying my new to me Kitfox, I started in on repairing by opening up that bay and making a tube straightener.

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I was able to get the tubes coerced back into alignment. Surprisingly they came out very straight and are not kinked. A spot on each longeron was a bit oval instead of round so had to make a die to squeeze the oval out of it. All in all it came out very good and I don't think it will cause any issues. I will have wait a few days for the Poly-Fiber kit to come so I can recover it.

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[109JB]

So moving on, the airplane isn't the cleanest example out there, but it seems a good solid airplane. There is some hangar rash and other not so pretty stuff that I'll have to take care of. The finish is polytone, which I'm not a great fan of because it is impossible to keep clean. It needs some TLC and also some upholstery.

On the upholstery end, it has absolutely none. The previous owners were using some cheap cushions. I intend to get some cordura fabric to make cushions, a turtle deck cover, and a baggage bag. Can anyone who has the stock Kitfox cushions in their IVlet me know how thick the bottom cushion and back cushions are?

[rv9ralph]

As far as cushion thickness, that depends on you. The proper thickness is what gets you to the most comfortable position to reach the controls and see over the dash. I added foam under my upholstered seat to get me to the right spot for me.

Ralph

[avidflyer]

Ouch, that had to wipe the smile off your face when you saw that. Seems like you are taking it in good stride though, press onward and get it back in the air. When it comes to adding things to an airplane, I'm reminded of the old adage, "if you want to put a part on an airplane that isn't absolutely needed, hold the part up in the air and then drop it. If it hits the ground, don't put it on" The moral of the story is everything adds weight, and weight kills performance in an airplane. Of course it ends up being a compromise, sometimes in the one direction, and sometimes on the other end of the scale. Hope you have fun with the new plane, JImChuk

[109JB]

Yeah, I was sick to my stomach when I saw it and still had over 3 hours to drive to get it home. When I got home it was 1:00 am, so just went to bed. After looking at it in the morning and taking my pocket knife to it I decided that it wasn't too bad. All together it is going to cost only about $100 to repair and that is all for covering materials. All of my poly fiber stuff is too old so I bought a $60 "practice kit" which will have enough to get it through silver.

As for the cushions, I realize I will need to customize, but I wanted to get an idea of what the stock cushions were, so if anyone has the thickness I'd still like to know.

I won't be adding anything unnecessary to this airplane. I actually want to make this one as light as possible. According to the logs, it is currently 560 pounds, but I plan to weigh it to find out what it is really at. I'll only be adding the essentials, and the upholstery is an essential to me but will only have what is absolutely needed to cushion my butt and hold an overnight bag.

Other things are going to get changed around slowly. I just plan to fly and have fun right now. The covering is solid, but it doesn't look too good. I love the polytone finish for repairs, flexability and durability, but am not a fan of the semi-gloss finish that seems to attract and suck in dirt. I eventually would like to recover this airplane with either Stewart Systems, or Oratex 600. I'm not a huge fan of the semi-transparent look of the oratex, but it may be worth it to save a few pounds. That's off in the distance though so I've got time to think about it.

[chipjumper]

So what exactly caused the tube damage on that flatbed trailer?


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[109JB]

So what exactly caused the tube damage on that flatbed trailer?


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So as I understand it now, the issue is that when hauling on a heavy duty trailer like I used, there is so little weight that the trailer suspension has very little give. Then you strap the airplane down and its suspension now has no give either. On top of that, with the wings folded they introduce a bending moment into the aft fuselage over what the fuselage by itself would have. Throw all of this together in a pot and add a bumpy road and you have a bent fuselage because the bumps are transmitted basically directly from the road to the fuselage with no suspension to absorb in between.

After it happened I did a bunch of reading and those that trailer successfully have trailers with soft suspensions and many support the tail a bit forward of the tailwheel at the cross tube in the fuse, both of which would help the loads overwhelming the fuselage.

I'll probably make an extended tongue for my 1200 pound capacity utility trailer and use it in the future.

[DesertFox4]

So what exactly caused the tube damage on that flatbed trailer?

1. Too heavy of a trailer by a factor of at least 10. Every road bump shock was transferred through the entire aircraft.
2. Tying any part of the fuselage to the trailer deck, such as shown in the photo, with the tie down straps. Only the landing gear should be strapped to the trailer thus allowing the landing gear to absorb stresses induced from rough roads.
3. Transporting with the tail on the trailer deck and not elevating the tail and using the tail mounting tubing located ahead of the tail that goes from side to side utilizing a tail elevating transport bracket. A few Kitfox aircraft have broken their vertical tail posts transporting with the tail tied down to the deck even on light duty trailers. This damage cannot readily be found without very close inspection.
In effect by tying the fuselage up front and the tail you turn your aircraft frame into a torsion bar which tries to prevent that heavy trailer from flexing during transport. The airframe always looses as evidenced here.

I’d be doing a thorough inspection of this entire aircraft before next flight and if the original poster is not an A&P, have one inspect the repair for compliance with best repair practices and look over the rest of the aircraft for further issues.

[109JB]

I appreciate the concern. The airplane will be fully inspected by both me and the A&P that is going to do the condition inspection and he was consulted on the repairs before I started them. I will say however, that being the original builder, an A&P, or anyone else doesn't mean that someone is or isn't qualified. I know a couple A&P's that I wouldn't let hold my coffee, and I know even more non-A&P homebuilders that I would trust with anything.

[DesertFox4]

Happy to hear you are doing a thorough inspection before flight. 👍
Congrats on your purchase. The model 4 is a lot of fun. Sorry your aircraft was injured on the trip home.☹️

[109JB]

I had to go out of town for a couple days so things slowed down a bit. After getting back i was able to get the fabric on and up through silver tonight.

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After the fabric is finished I don't plan to do a lot of mods before flying it, but do have some routine maintenance stuff to do mainly to establish a baseline for the future. I have some ideas of what I want to change but I'll get some flying done first and see if those opinions change.

[Goldknight]

Thanks for sharing this. I am picking up a Merlin GT in the spring and I only have my 25ft 14K trailer. Great info. I have some planing to do that i was unaware of

Thurston

[efwd]

Thurston, look at my thread (EFWD), page 27 at the bottom you will see what Josh Esser did to support the airframe. I did as he did and it made it to the airport unscathed.

[jmodguy]

I would NOT recommend Stewart systems. PM me for details

[109JB]

Thought I would update.

I still haven't flown it because I have been very busy with work which has curtailed the time I have available to work on it. I did however get the fuselage damage all repaired.

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The color looks perfect in the picture, but it actually does show a little. The shad of the repair is just a bit lighter. I'll deal with that later. I also had to do a little patch on the flaperons.

I also made some seat cushions and they came out pretty good I think. I made them with memory foam and fabric that is used for patio furniture. Could have done some wild prints, but chose plain old black. I had the foam and the fabric cost me about $25. They will do for now.
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I also made some brake pedals for the right side and got them all hooked up and working. I only had blue paint, so they stand out a bit.
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I've been working on fixing other things up and getting to know the airplane. Kind of getting a baseline for it so I know what I've got. I had a leak coming from the gearbox that was a seal issue. I think I have that fixed now but will keep an eye on it. Then the tach was working but crapped out during one of my test runs so had to replace it. I just put a cheap one in for now because I think I'll be putting an EIS on it this winter. I replaced all of the fuel lines. I think it is just about ready to go now so after a little more run time to verify that the gearbox leak is fixed I'll get it over to my mechanic for the condition inspection.

I did have a question though. This airplane has the 582UL engine and it is pretty rough at idle speeds, which I suppose is "normal" because of the big prop out front. Being a snowmobiler, I know that the 2-stokes are smooth runners and verified it by running the engine without the prop on. The 582 UL ran smooth as glass at 1900 rpm whereas with the prop on it it didn't smooth out until about 2500 rpm. I'm thinking about investing in a clutch setup for it and am looking at the Air Tech clutch kit sold through ACS. https://www.aircraftspruce.com/catalog/eppages/clutchrk400.php?gclid=CjwKCAjw-vjqBRA6EiwAe8TCk_szSY61HRkgdzq5YW2HYUnlJpXMo26S69v nyh88xk0KCNeqep4PMhoC1w0QAvD_BwE

I would love to hear from anyone who has experience with any clutch on the 582, and especially those that have experience with this clutch kit.

Thanks,

John Brannen

[Av8r_Sed]

I run that clutch on my 582. Also known as an RK400. It’s been very reliable and makes the idle just like you’ve experienced. I even had to put in a smaller idle jet and file my carb slides a bit so it idles nicely at 2000 RPM.

The down side is you can’t rotate the engine when it’s shut down. That makes it a pain to inspect the pistons and rings. If I had a lighter prop, I’d probably remove the clutch, but for now I’m sticking with it.

[109JB]

Thanks. I didn't think about not being able to rotate the engine for maintenance. Sounds like otherwise it is a plus.

[Av8r_Sed]

Forgot to mention: On approach when the clutch disengages, the windmilling prop really increases your sink rate. I always add some power to arrest that before touchdown. Deadsticking it in takes a bit of skill and can lead to some interesting arrivals. On the plus side, you can get it in pretty short.

[109JB]

Well I was finally able to get get enough instruction scheduled to get to the point where I finally flew my Kitfox solo today. It was rough getting the time to do it with weather delays, my father went in the hospital, kids things, scheduling conflicts with my instructor, etc. It finally happened though and it was fantastic after basically no flying for the past 10 years. It was a little reminiscent of my first solo 37 years ago with the instructor saying "Just pull off to the side and let me out."

[sturdee]

Congratulations, on getting a Mk4,
pitty about the damage ,there should be a check list on towing the fox for those who have never done it before.
I would say from looking at the pictures on the Trailor you where very lucky with just the top longeron needing repair.
1; get a couple of leading edge braces made or purchased to support the wing when folded, there’s an awful twist load going on to the pivot point ! Check inboard rib to spar scotch weld for security,
2:long distance towing jack up the tail spring and place a suitable block of wood under the tail spring before ratcheting down. Do this before folding less weight on the tail .
3;secure the flaperons so they don’t bang against the tail
4: fit a tube onto the fuel cap vents and secure over the wing to take any fuel sloshing away from plane.
5: cover the turtle deck area well as water weather will ingress your cockpit,
nice job on straitening the tubes , enjoy ! Safe flying

[beeryboats]

I wish you were closer to Indianapolis. Not being a two-stroke guy, I'm not sure what I'm dealing with on my 582. What prop are you running? I can only get mine up to about 5500rpm. I'm running a Warpdrive with about 11 degrees at the tip. Can you share some specs?
Not trusting the tach, I bought a TinyTach but I'm not sure I have it at the correct setting. I'll call the manufacturer tomorrow and ask. But in the mean time, I blew all the dirt out of the barn tonight! Just at idle though, wanted to make sure it was working....:cool:

[109JB]

I'll see what I can do to get you better numbers the next time I fly. I had given you some earlier but I also since found that my primary tach was off and was reading higher than actual RPM. I installed a new tach AND a tiny tach copy, AND i compared them to my optical model airplane tach and all three now match pretty well. Earlier I had said that I was getting 6800 rpm after takeoff at full throttle, and that is what the old tach said but now I can say that my actual RPM is lower than the maximum of 6800 RPM. It is more like 6400-6500 rpm and the airplane performs just fine. Next time I fly I will do a static RPM check and report back to you.

[109JB]

I have had some time to do some practicing and I made a couple videos. Although some of the landings aren't the prettiest, I'm pretty happy with my performance considering I only have about 6.1 hours after essentially not flying for the past 10-12 years.


https://www.youtube.com/watch?v=aqetOIWxXZw&t=213s


https://www.youtube.com/watch?v=eCy_oUjmPDY

[efwd]

So fun. Thanks for posting. Always fun to see terrain that members are flying in. I would certainly enjoy flying over flat land. All the hills and mountains out here make for bumpy flights. These damn Santa Ana winds don't help either. This morning they happen to be making a wild fire here look like a blow torch.

[109JB]

I've been doing more flying and more experimenting with approach speeds, flaps, etc. Since my last airplane was a Twin Comanche that I approached at 105 and came over the fence at 80 with I have been working slowly to get my approach speeds down in the Kitfox. I started off at 60 mph approach speeds but that seemed to cause excessive float and eat up lots of runway. Now for solo "normal" landings I am approaching about 50 mph IAS, transitioning over the fence at about 45. This has been working ok for me for any flap setting. I'm doing pretty well but wondered what techniques others are using. If you experienced Kitfox IV flyers could let me know what your landing techniques are it would be appreciated.

[t j]

My landing check list in a Model 4 is FFFF:
Fuel,
Flaps (None for 3 point, an inch or two for wheel landing)
Fifty MPH on final,
Feet off the brake pedals.

[4Hummer]

Looks like you need to do the pedal re-enforcement There's a Service bulletin for it, and kit/part available from kitfox

[109JB]

Looks like you need to do the pedal re-enforcement There's a Service bulletin for it, and kit/part available from kitfox

Thanks for your concern, but you are mistaken. There is no Service Bulletin for the K IV rudder pedals. The only rudder pedal Service Bulletin applies only to the Vixen. There is a Service Letter to inspect the rudder pedals of all models and to replace if cracks are found. I have accomplished that. No cracks found. The service letter does advise using the factory reinforcement kit part number 35015, but it is not mandatory.

I do plan to reinforce my pedals, but will not be using the factory kit. The kit is geared toward non-welders and as such uses riveted on steel gussets. I will weld boxed gussets on which will be substantially stronger than the factory mod. Here is picture I found of what the factory kit looks like. Not that the factory kit isn't sufficient, but I can do better, so will be doing it different.
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[4Hummer]

Service Letter / Service Bulletin, Tomato / Potato.. Was just giving you a heads up on a known issue with those pedals

Agree if you can weld it's a better and cheaper option for sure. Kitfox want something like $185 for the reinforcement kit,

I'm picking my New to me Model 4 up this weekend, it's how I came across the Peddle issue

[DesertFox4]

Great reminder 4 Hummer. We have new members all
the time and new owners of earlier models and even after all these years
some aircraft have not reinforced their rudder pedals. When they break
on landing or take off it can ruin someone’s day.👍👍