PA-12 Build

Wayne,

I was in the exact same position 3 years age myself. While it at the welder, you should definitely consider the 1935# weight increase. It gives you the extended baggage and cargo door mod. Maybe the list should be....

1935# gw increase with cargo door (bigger like MCS Mike does)
Left gear seaplane post
lower dogleg
PA-14 cathedral
Float fittings
PA-18 elevator controls under the floor
PA-18 gear fittings
skylight
move the door hinge up for seaplane door(I really like mine) maybe 1 gauge heavier above the door to attach the hinge
enough tabs for your extended baggage floor and new tabs for the regular floor and tabs for your interior panels (Kydex?)
figure out where you want the trim handle so the cables don't run thru the extended baggage
shooter window?
bigger lifting handles on the tail
tabs for metal belly under the tail (you can make it nice so it's not a snow scoop)

Here's some of what I did and other things I wish I would have.

Also, I forgot to mention the removable rear seat crossbar. Makes getting into the aft baggage a lot easier. I'd consider it a must and it's an easy mod. Buy the stc from Ken Rivard but make it a little better by having the tabs face up. Do a search, it's been discussed before. While your there make the lower seat bars removable like a -14. That way you'll be able to install the flat floor easier all the way back. I used epoxy coated wood for the floors, but if I had to do it again I'd use aluminum. I like the idea of diamond plate but think it's too heavy. I bet .032 would be fine for the whole thing or maybe .047 up front and .032 for the cargo area. Wonder what the thinnest diamond plate you can get is.......hum?

X brace the top deck if it hasn't been mentioned

So did Atlee Dodge get their STC for the removable crosstube for the PA12? I read an old post that said they were applying for one....
John

working on my 12 now and a couple of clarifications to your post:
The gross weight increase is probably from Charlie Center @ Crosswinds. The dogleg extended baggage is a different stc, probably from Ron Sullivan. Still not clear if the upper baggage is part of Charlies GW increase.
the Gullwing door and modification to lower the door base makes getting in and out of the 12 easier. That is another STC from Crosswinds.
you may also want to look at the pa-18 seat mod with the battery under the front seat, but that gets pricey pretty quickly. An Atlee Dodge STC
i alos opted for the cub crafters fuel system stc to get rid of the header tanks, and put in a fuel valve with on/off/both as well as left and right.

The gear mod for pa-18 removes the 12 mounting and effects the seat mounting. So I mod'ed my seat to mount like the 18 seat and will sign it off under the gear STC.
When I first got my 12 I leveled the frame on gear and the left tire was 8" off the ground. Nick Smith in Canada repaired it like new. Amazing what a good welder can do.
Good luck with your project.

algonquin said:

The gear mod for pa-18 removes the 12 mounting and effects the seat mounting. So I mod'ed my seat to mount like the 18 seat and will sign it off under the gear STC.
When I first got my 12 I leveled the frame on gear and the left tire was 8" off the ground. Nick Smith in Canada repaired it like new. Amazing what a good welder can do.
Good luck with your project.

Click to expand...

Atlee has the STC for the -18 seat now

deetz said:

..Still not clear if the upper baggage is part of Charlies GW increase...

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I think thats in the drawings on his STC.... but i do a bigger upper door

i alos opted for the cub crafters fuel system stc to get rid of the header tanks, and put in a fuel valve with on/off/both as well as left and right.

Click to expand...

I have Air Energy fuel tanks with front and rear outlets and a Dakota Cub fuel valve with Off/Left/Right/Both and no header tank. Also, Super Cub sight gauges.

algonquin said:

The gear mod for pa-18 removes the 12 mounting and effects the seat mounting. So I mod'ed my seat to mount like the 18 seat and will sign it off under the gear STC.
When I first got my 12 I leveled the frame on gear and the left tire was 8" off the ground. Nick Smith in Canada repaired it like new. Amazing what a good welder can do.
Good luck with your project.

Click to expand...

The 18 gear mod does get rid of the interior bungees, but it doesn't necessarily affect the seat unless you want it to. Again an Atlee STC

deetz said:

working on my 12 now and a couple of clarifications to your post:
The gross weight increase is probably from Charlie Center @ Crosswinds. The dogleg extended baggage is a different stc, probably from Ron Sullivan. Still not clear if the upper baggage is part of Charlies GW increase.
the Gullwing door and modification to lower the door base makes getting in and out of the 12 easier. That is another STC from Crosswinds.
you may also want to look at the pa-18 seat mod with the battery under the front seat, but that gets pricey pretty quickly. An Atlee Dodge STC
i alos opted for the cub crafters fuel system stc to get rid of the header tanks, and put in a fuel valve with on/off/both as well as left and right.

Click to expand...

The 12 type certificate (or maybe it is the original drawings) shows the header tanks being an option, so no STC is needed to remove them. The Dakota Cub fuel selector and the sight guages are both very high quality and a great addition, as I recall cheaper than Cub crafters and they come with an STC.

Hi Wayne. Good to hear from you. I ran across your name recently at home while looking for something else. Glad to see you are progressing on your project. I look forward to following you along. I haven't been on .org too much lately. I need to get back to this site. This will be a good excuse to do so. Take care.

Kevin

MT12 said:

The 12 type certificate (or maybe it is the original drawings) shows the header tanks being an option, so no STC is needed to remove them. The Dakota Cub fuel selector and the sight guages are both very high quality and a great addition, as I recall cheaper than Cub crafters and they come with an STC.

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My 12 doesn't have a header tank or the front STC'd lines.

I've thought about putting the front lines in. But who in hell is going to be doing hard maneuvering when you're running out of gas?

Charley, All you will need to do is to have your nose too low when you're low on gas to stop the flow of whatever is left.

skywagon8a said:

Charley, All you will need to do is to have your nose too low when you're low on gas to stop the flow of whatever is left.

Click to expand...

Yeah I think when I rebuild it I'll put in the front lines. That's the way it came when I bought it.

Looks like a great project!!!

Yeah I think when I rebuild it I'll put in the front lines.

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Left-front is pretty easy; right front less so.

Charlie Longley said:

My 12 doesn't have a header tank or the front STC'd lines.

I've thought about putting the front lines in. But who in hell is going to be doing hard maneuvering when you're running out of gas?

Click to expand...

power on long or steep decent

Early in 2005, I had located an IA who was knowledgeable about Cubs, and, just as important, was local to me. In Feb/March, '05, he picked up my fuselage and brought it to his shop. Keep in mind that Univair did not yet have their jig ready for producing fuselages. One of the first things we attacked was the crushed right doorpost. The plane had landed upside down after it broke loose during a windstorm two owners ago. It bent the spars and lift struts, smashed all of the wing ribs and fuel tanks, broke the flywheel and twisted the fuselage. Much was repaired by the PO to some extent.

We cut the door post and jacked the fuselage internally to square things up. The right front wing attach point was quite a bit lower than it should have been. I can't imagine how stall/spins would be in this configuration.



We installed a Sullivan extended baggage, X brace, -14 cathedral, -18 landing gear tabs and cabane, float fittings, elevator controls, repaired the jackscrew tower, sleeved the tailspring mount, new door trim, replaced the doorpost and a few other tubes in the cockpit area, -18 trim system, boxed the tail, replaced the D window frames, replaced some of the piper channel for the boot cowl and false cowl and missing pieces for the skylight.

The fuselage was then blasted and checked for perforated tubing.



The fuselage returned to the hangar in September, 05. My wallet was also quite a bit lighter too, so the trip back to the airport was easier. I treated the bare metal with "A Must for Rust" recommended by Kent White for preventing flash rust from forming on bare metal. This gave it a blue-ish tint. When I got it back to the hangar, it was time for more evaluation. That is what you do when you don't know what the next step should be.



Next step? Maybe work on the wing until I can figure out what to do next to the fuselage. We had not really addressed the condition of the longerons in the way of the jackscrew tower and tailpost. They were not perforated, having been replaced after the wind storm, but I thought they were still a mess.

Wayne

I have to say, I'm feeling its time for an update

You are quite right... time for an update. As I write this, I have to dig back into the dusty, cobwebbed recesses of my mind.

I moved the fuselage to my garage so I could spend more dwell time on it. If you remember from my early posts, the plane had been blown over in a wind storm in it's previous life. The wing tie-downs broke and the tail held. When it went over, it landed inverted hard enough that the flywheel/starter ring broke on impact. The wing tops were stove in and the fuel tanks were flattened, making their capacity closer to 9 gallons.

All of this damage had been repaired (after a fashion) and the plane returned to service (sort of) prior to me purchasing it.

With it now residing in my garage, I was able to evaluate it frequently. I purchased a set of ribs and fuel tanks from Dakota Cub. I also purchased spars to replace the ones on the left wing, which the PO had patched by putting two doublers on the web inboard of the lift struts. My IA talked me into installing flaps, so I purchased the flaps and kit from Dakota Cub. I also upgraded the landing gear to SC gear. I found a local 290-D2 for a good price ( false economy) that needed "just a bit of work" to make well.

I happened by the Univair booth at OSH and discovered that they were selling repair sections for the fuselage on 12s now. I ordered and received the "short" section, which included about 8' of longeron forward of the tailpost.



Now, to find someone that had a -12 jig and the capabilities to weld it on and assure that the rest of the fuselage had been returned to square.

I loaded the fuselage into the truck early one morning and set out for the shop. Driving around Minneapolis during the morning rush with 10' of extended load woke up a few drivers, I suspect.



Approximately eight months passed before the fuselage made it into the jig. And then, it was discovered that the tailpost was off plumb by about 5 degrees. Univair was contacted and they exhibited OUTSTANDING customer service by shipping a new one and accepting the other one by return freight. Thank you Jim.



A month or two later, I took delivery of the fuselage.



In the interim, I retired from my day (and night) job and purchased a hangar at the ANE airport and met Darrel Starr, Windonhisnose and a bunch of the SC.org folks who reside there and around the area. The hangar was an empty shell of a pole barn. If I was to be able to work on the plane during the winters, it would need to be insulated and heated.



Next up: the rest of the modifications, hangar updates and what have I been doing since I got the fuselage back in 2012

I'm curious, who did you take it to for the jig work?

The fuselage never ended up in a jig. It was attached to a "table" made up of two I beams welded together and ground flat and level to 0.030" end to end and diagonally.



The work was done at Jay's shop in Brainerd, Javron Inc. It happened at a bad time for scheduling. He was in the middle of building his new shop for manufacturing Cub airframes and there was not enough room to set up the -12 jig in his old shop.

The table was a compromise but I am confident the fuselage is as straight as it will ever get. He did a great job on it and it was worth the wait.

Wayne

Is this project still ongoing? THANK YOU for posting all the pictures!! This has really helped me to see under the skin of the PA-12 and helped to understand mine!! I'm currently wondering how to get access to some of the stuff that's under the outer layer of fabric (over the stringers) and outside the frame fabric itself in the cockpit area, for example fuel switches, trim assembly, fuel pipes etc.

Question: can I just cut holes in the inner cockpit fabric, for example at port rear, covering the trim cables etc, or is this fabric area part of the overall "stretched and stresed" fabric and therefore any holes should be contained within glued on rings etc?

Philly5G said:

.
Question: can I just cut holes in the inner cockpit fabric, for example at port rear, covering the trim cables etc, or is this fabric area part of the overall "stretched and stresed" fabric and therefore any holes should be contained within glued on rings etc?

Click to expand...

you could remove all of the interior if you wanted to... not structural...

mike mcs repair said:

you could remove all of the interior if you wanted to... not structural...

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Thanks Mike!! The other PA-12 at my airfield has solid panels, where I have fabric. Which was the original fit when the aircraft were originally built?

Wow. 13 years and untold thousands of dollars in mods. Looks like it could be a nice one when you " getter done". Hope it turns out for ya! Your a much braver man than me........ And have the patience of
Jobe.
Wishing the very best on this massive project!
Best of luck
E

Philly5G said:

Thanks Mike!! The other PA-12 at my airfield has solid panels, where I have fabric. Which was the original fit when the aircraft were originally built?

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Fabric.

But most everyone switch’s to aluminum or kydex


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Philly5G said:

Thanks Mike!! The other PA-12 at my airfield has solid panels, where I have fabric. Which was the original fit when the aircraft were originally built?

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Here’s some I made with kydex.

https://goo.gl/photos/HmUX41Zzr5sDagzDA
https://photos.app.goo.gl/HEgiiJwbFwE6gsaU8


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Thanks Mike, they look great! How did you attach them to the frame?


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