172 taildrager conversion

How to keep the Cessna 170 flying and airworthy.

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or170B
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Joined: Mon May 13, 2002 5:59 am

172 taildrager conversion

Post by or170B »

Well gentlemen after a couple years of looking for another 170B with a 180 Lycoming I bought a 1956 172 with the 180 conversion. The plane fly's just like a 170B except for the training wheel up front. I would like to change it to conventional gear. The STC route is very expensive, I was quoted $24K just for the parts from Stoots aviation. with another 12K for local labor. At $36k this out prices my checkbook. I have been thinking of using 170B parts and trying for a field approval. I can get all the pieces for $5k used. Does anyone have any recommendations for me? Has anyone you know done this? Any help is appreciated.
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n2582d
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Re: 172 taildrager conversion

Post by n2582d »

While the price may not be to your liking I’m impressed with what I see on the Stoots’ website. New parts, Pponk fittings, refurbished gear, etc. His is STC SA02376AK. Del-Air’s STC SA5433SW was talked about some time ago here and here. At that time Del-Air was not selling the conversion. It might be worth calling Chris to see if that is still the case. Those threads also mention the Bush conversion, (formerly Bolen conversion), SA296GL, as one you want to avoid. Finally there is the Fravel conversion, SA553GL. This was being resurrected by the guy who developed and sells the “EZ Flap” flap handle extension. Long story short, it looks like he’s short of funding to get it to market. Read about it here. Reading that thread should convince you not to try the field approval route. In my opinion, $36,000 for Stoots’ conversion will be chicken feed in comparison to the cost of getting a field approval. Wouldn’t it almost be easier to find a damaged groundlooped 170 fuselage with dataplate and transfer your 180 STC and wings to it? The STC paperwork transfers I’ve done have cost less than $100. Del-Air’s Lyc. 180 STC SA00461SE is the same number for the 170 as for your 172. (Not sure if that’s the STC you have though). The FAA has recently come out with guidance on what constitutes a rebuild, Order 8100.19. The days of “rebuilding” an aircraft around a dataplate are over ... but if you have a 170 fuselage with tail feathers I believe the wings part numbers are the same.
Gary
or170B
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Re: 172 taildrager conversion

Post by or170B »

My 172 has the Avcon STC I don't think it would be easy to get ahold of them for a STC swap. I haven't heard anything good about them ever.
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n2582d
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Re: 172 taildrager conversion

Post by n2582d »

Del-Air’s baggage door STC is a paperwork only STC—i.e. you have to scrounge the parts. Maybe Chris can do the tailwheel conversion the same way???? Worth asking if you have access to the parts.
Gary
hilltop170
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Re: 172 taildrager conversion

Post by hilltop170 »

What do you intend to do with a tailwheel that you would not do with a nose wheel?

If it is something besides "I just want a tailwheel", buy a large fork for the nose wheel and put a larger tire up front.

I know guys in Alaska with early straight-tail 182s with 8.50-10 main tires and a 8.00-6 nose wheel that go anywhere a 180 can go.

And they can take off shorter than a 180 because they are already in a low-drag attitude and can rotate more without the tailwheel.
Last edited by hilltop170 on Tue Jan 01, 2019 11:47 pm, edited 2 times in total.
Richard Pulley
2014-2016 TIC170A Past President
1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
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ghostflyer
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Re: 172 taildrager conversion

Post by ghostflyer »

182,s and to a point 172,s have a issue of having a soft nose strut attach point on to the fuselage . We have had 2 nearly new 182,s snap the lower cast fitting that attaches the strut to the fuselage .these cost several thousand dollars from Cessna . There are cast/forge fittings on the inside of the fuselage that also cost a arm and a leg to buy and change . Plus the phenolic indicator straps that travel from top to bottom in the strut forging also cost a heap and are easily broken .
I have looked at the modified 182,s in Alaska with the big wheel up front and some of the mod isn’t legal as it’s not part of the big wheel STC. However after saying that all that sourcing a gear box to fit and fitting it is a BIG job. The fittment has numerous traps also. My 170A had its gear box replaced long before I obtained it and one of the guys that “claimed” he did the job made a claim they used a Cessna 206 gearbox. It’s a beautiful job , it’s looks like it came from the factory that way . The Rh gear leg is a perfect fit BUT the LH leg is a night mare with alignment. I would sell the 172 and purchase a 170 .its a lot simpler.
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GAHorn
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Re: 172 taildrager conversion

Post by GAHorn »

Transgender surgery is difficult and a money-loser. I don't advise it.
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suntiet
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Re: 172 taildrager conversion

Post by suntiet »

fravel STC You can find him hanging out on the backcountrypilot's forum.
Mayday
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Re: 172 taildrager conversion

Post by Mayday »

or170B wrote:My 172 has the Avcon STC I don't think it would be easy to get ahold of them for a STC swap. I haven't heard anything good about them ever.
Bob is still around and answering his e-mails at Williams.stc@gmail.com. I purchased the lycoming engine conversion STC from him a few months ago and he came through.
flyboy122
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Re: 172 taildrager conversion

Post by flyboy122 »

Mayday wrote:
Bob is still around and answering his e-mails at Williams.stc@gmail.com. I purchased the lycoming engine conversion STC from him a few months ago and he came through.
Out of curiosity, do you mind telling what he charged? My 170 has the Avcon STC and it would be interesting to know what it's worth in today's dollars.

Thanks,
DEM
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Bruce Fenstermacher
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Re: 172 taildrager conversion

Post by Bruce Fenstermacher »

Mayday wrote:
or170B wrote:My 172 has the Avcon STC I don't think it would be easy to get ahold of them for a STC swap. I haven't heard anything good about them ever.
Bob is still around and answering his e-mails at Williams.stc@gmail.com. I purchased the lycoming engine conversion STC from him a few months ago and he came through.
You are the only person known to have had a positive outcome in years.

Curious what you received? Any parts such as a motor mount?

Or just drawings?
CAUTION - My forum posts may be worth what you paid for them!

Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
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