bush L-4 project

just thought i'd share the progress on my own first plane. its a early # j-3 going experimental.
the wish list is as follows. some of this has come true
1. removed knee busters
2. x-frame nose
3. rear seat back chopped and moved back
4. extending the baggage, (not super cub sized)
5. "gun door" so i dont have to empty the bags to grab the shotgun
6. bellie pod mounts (so i can carry my RC bush cub)
7. float mounts
8. extended gear
9. saftey cables
10. 26 inch tires
11. scott 3200 tail wheel, (undecided on the leaf spring)
12. super cub elevator's
13. j-3 rudder for idenity purpose
14. nav, strobe and landing light
15. L-4 windows
16. left seaplane window with sliding windows..... with out seaplane door
17. micro Vg's
18. extended aileron style flaps
19. leading edge cuffs
20. booster tips, no matter how much everybody hates them
21. aluminum spars
22. maybe a early cessna 172 front seat (looking into clearances now)
23. windsheild defroster,
24. increase the cabin heat
25. 14 gal wing tanks
26. welded on turtle deck
27. super cub flat top windsheild
28. ergonomically freindly tail handle on left side fuselage


ive probably forgotten alot of things but thats the basic list. its not a super cub and im not a bush pilot so no x-frameing of the fuselage, minor beef up to the tail wheel attachment. and i'll hand prop the C-85 with either a Gen or a battery. hopefully some day i can afford a C-90.
with my income this is a $50 a week project so rushing wont be easy to do.


and now some questions

1. anyone know why early J-3's are not approved for the gross weight increase?

2. where are serial #'s located on early cub fuselages?

3. any leads on extended experimental landing gear thats dosnt cost 2 months of income?

4. is there a length differance between J-3, PA-11, PA-18 wing struts?

That's going to be an awful lot of weight for a C-85 to haul around. You aren't going to like the performance. The key to having short field performance with a small engine is to keep it very light. If you want that list of items on an airplane you need to start with a Super Cub.........not a J-3 because you are going to need a lot more engine. A J-3 with VG's, balanced elevators, and 26" tires perform excellent on 85 to 90 HP. You won't have enough power to carry around all that other stuff and my guess is that you will be unhappy with the performance if you add it to a J-3. Then there is the 1220 gross weight issues too. Just my 2 cents worth.

Steve

I'm curious how you are going experimental or did you mean LSA type? If experimental you will have to go with appendix 8 which spells out how "salvaged items" are allowed. Basically I think you would have to build everything BUT the fuselage and gear. Wings and tail would have to be scratch built . If keeping the type acceptance are you a licensed mechanic? I'm going the first route with a supercub fuselage. Looking at your pile of parts it looks like that's what you are planning too. Christian Sturm's site has the J3 wings detailed in the drawings section (also the supercub so be careful.) D&E sells aluminum spar blanks for reasonable. I bet your looking at wood ribs for lightness. Online metals pretty good for price and service on raw metal. If you haven't checked out Marty's 2+2 site, it's basically a "how to" for the tail building stuff. Mines been going on far longer than I thought it would but the fun factor has increased as need to finish has gone down. If you have need to fly while building get a Quicksilver MX or Sprint for 3-6K and fly all you want for nothing while enjoying the build!

Just to clarify, I have the Super Cub wings on my site, not J-3. 13 rib and 16 rib. Drawings 12278, 14394

As far as the use of the J-3 fuselage and parts of it will depend on the DAR. I've seen it go many ways. Not suggesting anything illegal but I know of many experimental category cubs flying around with part of a piper soul.

Bugs66 said:

Just to clarify, I have the Super Cub wings on my site, not J-3. 13 rib and 16 rib. Drawings 12278, 14394

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Bugs I may have it wrong but there are two spar layouts on the site. In drawing 14383, for example, isn't one for J3? Layout 14383-2 and -3 are for J3 according to the remarks section or do I have it wrong? If so I'll edit that first post to get rid of the reference so it isn't cast in stone for a hundred years.

qsmx440 said:

Bugs I may have it wrong but there are two spar layouts on the site. In drawing 14383, for example, isn't one for J3? Layout 14383-2 and -3 are for J3 according to the remarks section or do I have it wrong? If so I'll edit that first post to get rid of the reference so it isn't cast in stone for a hundred years.

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I don't have a J-3 parts catalog to verify so cannot say what -2 and -3 are for. Maybe for PA-11? The same drawing shows a dotted outline however for -4, -5 which are PA-18 up to -135hp. Unfortunately I do not have the drawing for 14391, PA-18-150. If someone can lend me 14391 I can make a PDF and put on my site.

qsmx440 said:

Bugs I may have it wrong but there are two spar layouts on the site. In drawing 14383, for example, isn't one for J3? Layout 14383-2 and -3 are for J3 according to the remarks section or do I have it wrong? If so I'll edit that first post to get rid of the reference so it isn't cast in stone for a hundred years.

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That is correct...14383-2 and -3 are the metal spars for a J-3 per the Piper J-3 Parts Manual
DaveG

Bugs66 said:

I don't have a J-3 parts catalog to verify so cannot say what -2 and -3 are for. Maybe for PA-11? The same drawing shows a dotted outline however for -4, -5 which are PA-18 up to -135hp. Unfortunately I do not have the drawing for 14391, PA-18-150. If someone can lend me 14391 I can make a PDF and put on my site.

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Maybe It's the spar layout and a few other parts only. I know I seem to run into parts called out for the J3 in the various diagrams. It's just called out in the "remarks" section of that diagram. So some of the "parts" seemed to be on your site but not complete assemblies. I don't know that much about the J3 but the diagram shows the J3 spar 11+" longer than the PA18 and that would make sense since it runs to the center of the fuselage.Chasing the dimensions around between the J3 and PA18 on those diagrams requires a lot of care. Hopefully there is no errata in dimensions

qsmx440 said:

Maybe It's the spar layout and a few other parts only. I know I seem to run into parts called out for the J3 in the various diagrams. It's just called out in the "remarks" section of that diagram. So some of the "parts" seemed to be on your site but not complete assemblies. I don't know that much about the J3 but the diagram shows the J3 spar 11+" longer than the PA18 and that would make sense since it runs to the center of the fuselage.Chasing the dimensions around between the J3 and PA18 on those diagrams requires a lot of care. Hopefully there is no errata in dimensions

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Bugg's site actually has quite a lot of J-3 parts....some of them are hiding in plain sight....For instance he has the PA-11 firewall drawing....
It really helps to have both the J-3 and the PA-18 parts manuals handy when going through Piper drawings, as the drawings are not marked well. It seems like Piper tried to obliterate the model call outs when they gave the drawing package to the Air Force....

Your going to have trouble with a 18 windshield and a J3 boot cowl, the J3 WS has a different angle and the boot cowl is higher then the Pa11 and 18 boot cowling.

Glenn

I am working on a new drawings web site, that will be much better than I have now. It will allow community involvement, comments, erratta, revisions, etc. It can support multiple aircraft.

On the firewall, the boot cowl 12381 is for the Super Cub. It calls for firewall 12365 which is on my site.

cubdriver2 said:

Your going to have trouble with a 18 windshield and a J3 boot cowl, the J3 WS has a different angle and the boot cowl is higher then the Pa11 and 18 boot cowling.

Glenn

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And to confuse the issue even more... There are 2 different PA-18 windshields. One for the -95 that has the steepest rake angle, and the Lycoming windshield that pulls the bottom edge back a bit to clear the air vent.
DaveG

it'll have to be an "experiment" when i get to the windsheild.
as for weight. i'll probably weigh as much as a radio filled wartime L-4, with a 115 lb pilot. she'll have to do untill i have the pockets to go from pony's to horses, and then feed them.

living and working in the aviation industry, 24 hr maintenance, restoration and, fabrication, ive been assured, going experimental is not a problem for me.........theres wag aero plans in my shop and i know how to use them. ;-)