PA-12 to PA-18 Landing Gear Conversion STC Question

My understanding is the verbiage between the Crosswinds and Sullivan STCs differ in regards to their specificity. One of them is more generic in specifying the type of gear you can use in the conversion, which allows for 6” extended gear. I looked around and couldn’t find this info. Does anyone know? I’m converting to 3” extended but would prefer buying the STC once in the event that I decide to go to 6” extended one day. Thanks in advance!

I converted with Charly Center's STC and assistance. He was very helpful. Crosswinds STOL. No problems. I do think, however, if doing it again I'd stay with the stock -12 gear arrangement, with less "stuff" hanging out in the prop wash. But I don't go back and forth to wheels and floats, and I don't do the real rough stuff.

AZinAK said:

My understanding is the verbiage between the Crosswinds and Sullivan STCs differ in regards to their specificity. One of them is more generic in specifying the type of gear you can use in the conversion, which allows for 6” extended gear. I looked around and couldn’t find this info. Does anyone know? I’m converting to 3” extended but would prefer buying the STC once in the event that I decide to go to 6” extended one day. Thanks in advance!

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It's pretty easy with either STC to go to 6" extended with a field approval. I have Crosswinds. I would disagree with staying with stock -12 gear, it sucks. With -18 gear it's a piece of cake going to floats and back. Also you can run AOSS suspension. I run 3" extended, AOSS and 31" bushwheels. You can also go on 35" bushwheels with -18 gear. Changing bungees on -12 gear sucks. Plus with -18 gear you get rid of all of that structure in cabin and use a -18 seat with adjustment and underseat battery.

Well if you wanting to go for 6" extended gear it is sweet on a PA-12 for sure! I have it on my Cub with AOSS and 31" tires /wheel skis. However on our PA-12 we still have
Standard Piper gear and it works just fine, same as it has for almost 80 years! It is not as convenient as 18 gear when it comes time to change it for floats, but considering
It will be in the God knows how much range ??? To convert it to 18 gear cost. The gear and shocks with new Cabane V, are just south of $7000! To cut fabric back and Tig weld on brackets if your already covered at any shop at today's rates , with fabric repairs ??? $1500 minimum.
So realistically with new steps and new safety cables your shoving $10,000. So it's a HUGE deal to do it.......
And for what it's worth: It is NOT a big deal to change the bungees. But I realize it is for most folks. I am with Gordon on this one, Cruiser gear works just fine 98% of the time, for most folks. However if your going to pretend your an Alaskan BP( or actually are, lol) and decide your going out into the " wild side" then you better just pony up the ten grand and get after it.......... ( Be good idea to have a $50,000 slush fund) for you first fender bender.
That usually goes hand and hand with long props & big rocks!
I prefer 6" gear, for ski flying but wouldn't bother with it otherwise.
Good luck with what ever you decide!
Fly safe;
E

When I built a -12 the best option for increasing AOA with all-around utility was PA-18 3” extended gear (FA Dodge STC) and 31” Bushwheels. It’s a great combination. The only thing I might do differently today would be to use 35” Bushwheels. And I’d ask for welded fuel steps on both sides and modify a long step to mount lower on the gear as a mid step, or just use Airframes’ super duty gear that has the step welded in.

What a -12 really needs is Pstol flaps. Has anyone been successful with that installation?

stewartb said:

What a -12 really needs is Pstol flaps. Has anyone been successful with that installation?

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This is an -12 Experimental, with slats and PSTOL flaps. Looks darn sexy to me.

https://www.youtube.com/watch?v=-OML9RcUFdk&t=8s&ab_channel=AeroncaChump

What I've found in regards to converting a PA-12 with stock landing gear to PA-18 landing gear.

SA148AL- Roger Borer
SA543AL- Ron Sullivan
SA669AL- Crosswinds STOL

SA550AL- Ron Sullivan (6" gear installation. Requires conversion STC previously completed)

stid2677 said:

This is an -12 Experimental, with slats and PSTOL flaps. Looks darn sexy to me.

https://www.youtube.com/watch?v=-OML9RcUFdk&t=8s&ab_channel=AeroncaChump

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This is my buddy's -12. It is my dream setup and may be a good representation of how my -12 will be setup when I eventually rebuild/recover mine. Beautifully done.

My buddy owns its -18 brother that he bought off of Nathan. Good cub. James and Nathan do a good job.

If you’re starting with a bare frame, what’s the cost of adding the -18 gear at rebuild? 10k?

Kodiakmack said:

If you’re starting with a bare frame, what’s the cost of adding the -18 gear at rebuild? 10k?

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Depends on if you're getting rid of the -12 bungie frame which is cutting and welding. Besides that, it's about $250 for the cabane V fittings, ~$500 for the -12 cabane V, ~$900-$980 for each gear leg depending on standard, 3" extended or 6" extended, ~ $120 per strut, ~$1,800 for hydrasorbs and then a bolt kit, brake lines, safety cables if wanted and bungie covers. These figures are all off the top of my head. So, about $5,000-$6,000 in just parts.

Just remember putting cub gear on a 12 slows you down 8-10 mph. My experimental will be built with the truss and cabane fittings.allowing 3" extended 12 gear and all the 18 landing gear options. Build for your mission not because somebody thinks you should.

Here is the actual price of 3" extended gear leg, with fuel step/ middle step unpainted, from their Website. It's $3240 just the pair of legs, plus Shipping......
The price for hydro sorbs is actually:
That of course doesn't include lower shock tubes.... So by the time you add up the Cabane, welding, fabric work, new set of safety cables you are going to be, right at the 10 grand.
This is very expensive MOD.
Very nice, but very expensive when you may realistically be able to do 99% of what you will with your new Cub gear
With Cruiser gear. ( And cruise 6/8 mph faster) If you don't have floats and are just running tundra tires all time, Cub gear is a personal call but ALOT of folks have done it, that probably don't need it..........
Good Luck either way
E