Bringing a Model 1 back to life

[Good old number 29]

Hi, I recently acquired a Kitfox Model 1, serial number 29, with a 503 Rotax. Yes, I'm smiling. It's been sitting for seven years, since some ravens pecked holes in the top of the wings, sitting at the airport. The fact that it sat so long was probably partly due to the fact that the last owner (I'm the fourth) also had another Kitfox to fly.
So, I got right into it. I went through the basics, then fired it up and taxied around the yard. Obviously, I'm not flying it until I get EVERYTHING in proper working order, but there's no way I could say no to taking a test drive. Fortunately, I have a small yard, so things didn't get out of hand. Once I had my fun, I got down to business. I have a short list from the last Conditional Inspection, that needs to be taken care of. Adding to that, the fabric repair, a thorough check of the engine, refinishing the props, replacing the windshield, and a couple issues I found with the brakes. But wait, there's more...
I got it in the shop, late last night, and started work on it this afternoon. I pulled the doors, seat, and the cowlings, and drilled the rivets on the sun-yellowed windshield. It came with a new one. I removed the engine so I could drain the reduction gear oil. Like new, no metal or anything. It only has 196 total hours on it. The engine mount bracket is going to get notched so the gear oil can be changed without removing the engine. There will be a little touch up painting on the engine mount and under the seat.
I noticed a little bit of gas on the six gallon aluminum wing tank. It had been repaired somewhat recently, but it has a bit of a drip. Not enough to notice, until I removed the stainless steel cover on top of the wing, that was put in place last time it was repaired. I might see if the weld is just cold-lapped, but most likely, I'm looking at a new tank. I had already called Kitfox to ask stupid questions, and got the impression that they could not care less about my Model 1. Sorry, I can't afford a new plane. What I did find out, is that it's about twelve weeks lead time to get a new tank built, and it's about the same cost for the 13 gallon tanks, as for the 6. They said I need to know the wing twist. I didn't really get an answer when I asked about the best way to measure the twist. I was wondering where the most appropriate places would be to measure. Reading the manual, it appears that it would have a 2" twist, measured spar to spar, at the ends. I'll measure it to be sure. I guess the twist should be measured at the center of the spars, on the end ribs, and not clear to the trailing edge? The rib goes under the rear spar, and not the front, but that won't matter, because they're all the same. Common twists were 1 3/4" or less, from what I found online. So, if I level the root rib, between the spars, I'll check level at the end rib, and measure the gap. Right? He did give me a little insight into what a project it would be to switch to the 13 gallon wing tank. I've gotten a look at the drag, anti-drag structure, and looked at the few pictures that members here have posted of their 13 gallon wing tank retrofits. And, of course, I've read all the nightmare stories of the problems with the fiberglass tanks. It's enough to make me wonder why they don't just gear up to make plastic wing tanks that could fit any twist. It is possible.
All this leads to my next little problem. I opened the valve to drain the wing tank into the panel tank. If you're wondering, both tanks were empty, and I put fresh, clean fuel in them. I was considering whether I could get by with just the panel tank, and save some weight by removing the problematic wing tank. I really wanted more capacity, not less. So, the fuel was draining into the panel tank, when I noticed a wet spot on its left side. Sure enough, the plastic on the panel tank was cracked about 1 1/2', 2/3 of the way up the tank. I pushed on a suspect spot just above that, and it cracked, too. That left me with zero good gas tanks. I really don't want to wait twelve weeks for wing tanks. Twelve weeks for one, six gallon tank, is a rate of two weeks per gallon. I am considering fabricating my own panel tank out of aluminum. I could have that done really nicely in a couple days. It's still not much capacity, even if I can stretch it a little. Are there any options out there? Maybe someone has a panel tank to sell. As I see it, the best, most expensive, and most time consuming solution is tear into both wings and install two big wing tanks. The biggest downside would be the added weight. Can anyone tell me what the 13 gallon tanks weigh? If I get rid of the panel tank, I'd be losing forward weight. I'd sure appreciate input on tanks and configuration. Remember, this is a Model 1 with a 503. Empty weight was 414 pounds, and I don't want to increase it, or decrease my useful load, and I don't want to end up tail heavy.
I'm considering the possibility of fabricating a light panel tank, and ordering the wing tanks, to be installed next winter. That way, I could run light, slap some patches on the wings, and get it in the air with a minimum amount of fuss. I'd almost have to leave the wing tank in (maybe I can fix it), since all the structure is gone from that bay. Next year, I could take the time to cut out ribs and move braces to install the tanks, and then re-cover the wings. Speaking of fabric work, maybe one of you with experience with patches can point me in the right direction. I'll try to post good pics. I have to fix a couple false ribs, and there are a few rips and little holes on the top of the wings.
It came with the hydraulic disk brakes. One wheel has apparently rubbed on the caliper, and the left caliper is touching the rotor, on the piston side. I'll check that out. Might need to clearance the calipers a little, and replace pads, or something. The toe brakes are at a bad angle, so it's pretty much impossible to keep off the brakes while using the rudder. I'm going to relocate the top bracket to change the angle of the brake pedal. I saw a picture online where someone had solved that problem by putting wooden blocks on the lower, rudder portion of the pedal.
The carb boots need to be replaced, and I'm going to check the timing and replace the starter cord for good measure, before I reinstall the engine.
It came with two propellers, both three bladed wood props. Both could stand to be refinished. One, the better one, has a small split in the tip, which can be glued.
I found the doubling plates mentioned in Service Letter 8, in a box, and I was considering doing that, and the flaperon hanger reinforcement brackets mentioned in another Service Bulletin, too.
That's my project. I'm looking forward to flying it. I'd love to hear comments or suggestions on any of the laundry list of things to do to it, or your own experiences with similar projects. I'll try to get photos up in the morning.

[Good old number 29]

http://s1375.photobucket.com/user/Th...?sort=3&page=1

[avidflyer]

I sent you a private message. Looks like you have a fun project ahead of you! :-) JImChuk

[rv9ralph]

There are several issues you have to address, good luck. Remember to follow standard practices for repair. Here is a link from TeamKitfox on metal tanks and issues in replacing tanks: http://www.teamkitfox.com/Forums/sho...?t=4843&page=2

Also, on your prop, just glueing the split will not make it airworthy. I would check with the manufacturer. In the era, there is a chance it is a GSC prop. They are located in Canada and can be found online. Replacement blades are available.

Ralph

[Good old number 29]

I will be sure to follow proper procedures. I was told that the prop with the small split was a Canadian Propeller, but looking at their website, it looks like they service Hartzell props, but no indication they make their own. It had a CP logo that looks similar, and says Quality Canadian Products. The guy I bought it from said that it performed much better than the other one, which is a GSC. The GSC needs to be refinished. It just has urethane flaking off, but no splits.

[Av8r3400]

GSC propellars have a 5 TBR year life span on the blades.

[Good old number 29]

Thanks for making that valuable point, Ralph. I took both props apart, this evening. The logos are basically identical, but one says GSC, and the other has a stylistic “CP”. They are both marked:
66
10
A ten degree pitch equates to 28 inches, according to my reading on it. The best recommendation I could find on it calls for a 68x32” prop on the dual carb 503 with 2.58 reduction. It might be under propped, right now, but then again, a little smaller, lighter, and finer pitched prop isn’t necessarily a bad thing.
So, both props are 66”x10•. Interesting that one noticably outperforms the other. Overall, they’re both very similar. To the naked eye, the same in width and thickness, and same diameter. The main difference is the root.
The “GSC” prop has round bases that clamp in the hub, fitting a machined groove, with a hole for a mounting bolt to pass through, which locks them in at the same angle. The aluminum hub has flat sides where the blades enter it. The blade roots are round, coming out of the hub.
The “better” prop has a round, slightly larger diameter, plastic-coated aluminum hub, with only slightly protruding flat edges past the radius. The blades are contoured at the root, rather than rounded off. They are flat, squared root ends, that fit together in the hub, and attach with four bolts through each blade. Two to the drive plate and two through bolted through the hub fixture.
I think that the contoured root and the circular hub are what make the one prop outperform the other, with the same size and pitch. The GSC hub has those flat, square edges churning the air, as well as the rounded root. I’ll consider that if and when I replace it.
Any input on favorite prop? I’m kind of interested in the Ultra-Prop. They recommended a 60” prop on this engine, but I’m not exactly sure why. Maybe inertia with the B gearbox. I’ll be careful not to gun it, but judging by the oil, it’s in good shape.
I’ll try to determine whether the one is going to be a wall hanger before I ship them both to GSC for maintenance.
http://s1375.photobucket.com/user/Th...tml?sort=3&o=3
http://s1375.photobucket.com/user/Th...tml?sort=3&o=0

[jrthomas]

It sounds like your Model 1 spent several years with some exposure to the weather since you said Ravens poked holes in the wings. If those props were not stored in a dry place I would have some concerns. I have a fair amount of time flying a friends Model 2/582 with a GSC 3 blade. I was a good performer and gave good service for the few years he owned it. Another friend owned a Kolb Mark 3/582/GSC that spent much of its life tied down outside. I wasn't flown for some time and when it did the blades would change pitch. He could reset the pitch and torque the hub to spec but the blades would turn again resulting in a lot of vibration. He determined that being exposed to the weather, the humidity caused the wooded blades to swell and shrink in the hub. He did what GSC said not to do and milled a small amount off the face of the hub. This seemed to work. He sold the Kolb and it was flown from NC to Ohio so I assume his fix worked. I flew behind a 503 with an Ivo for years. They seem to work very well with a 503 with zero maintenance issues and they're the easiest prop I know to adjust pitch. Several friends had 503's with Ivo's and they all had good service and performance. I would think a good used one could be bought cheap. I bought an unfinished Model 4/912ul that came from Kitfox in '95 with a GSC. I never flew with it, sold it and bought a Kiev. James Thomas

[avidflyer]

I had an ultra prop years ago on a Quicksilver MX. Friend of mine had one on his Flightstar. They do make a lot of noise, and when my friend changed to a differernt prop, his performance improved quite a bit. It's not a prop I would recommend based on what I've seen and what I've read. I think the newer style Brolga prop blades are more efficient than the regular Ultra Prop blades. One thing to remember, prop pitch will effect your EGTs. A lightly loaded engine will run higher EGTs. That can be a recipe for disaster. I recently sold a couple of props that would have worked for you. A 64" 3 blade IVO, and a 66" 2 blade Powerfin. They belonged to a friend of mine who passed away last winter. JImChuk

[Good old number 29]

I’ve been looking at a lot of different props, and the Ivoprop looks like a good way to go. Hopefully, one or both of these that I have will be servicable, and I won’t have to buy a new one right away. I’m trying to keep expenses to reasonable amounts. The most econonomical thing to do would be to buy new GSC blades, if needed, but considering long term practicality, I might be better off with a composite. We get a fair amount of rain here, besides freeze and thaw cycles, which is hard on wood, if it’s left outside. If it works out the way I’d like it to, I’ll be able to plow in a grass strip, here at my place, and I can fold the wings and stuff it in the shop.

Matt