170A with the Sportsman STOL Kit?

How to keep the Cessna 170 flying and airworthy.

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Bhbackcountry
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170A with the Sportsman STOL Kit?

Post by Bhbackcountry »

Good Afternoon,

I'm going through the logs of what could potentially be my new 170A but I ran across an interesting entry. It lists the STC for the Sportsman STOL kit but when I look it up it only shows the 170B as approved. I've got a call into Stene Aviation but thought I would see if anyone has seen this kit on a 170A and if it's legal? Thank you!

Pat
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GAHorn
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Re: 170A with the Sportsman STOL Kit?

Post by GAHorn »

'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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Bhbackcountry
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Re: 170A with the Sportsman STOL Kit?

Post by Bhbackcountry »

Thank you. That’s where I was looking too. I was hoping there was an approval floating around that I didn’t know about. I’m curious what the next step would be since it’s already installed or if it’s even worth continuing with the prebuy.
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GAHorn
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Re: 170A with the Sportsman STOL Kit?

Post by GAHorn »

Bhbackcountry wrote:Thank you. That’s where I was looking too. I was hoping there was an approval floating around that I didn’t know about. I’m curious what the next step would be since it’s already installed or if it’s even worth continuing with the prebuy.
I would ask the last annual inspector how he approved that?

If you don’t get a basis of approval for it, you will own an airplane that’s is not approved for return to service. Move on.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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Bhbackcountry
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Re: 170A with the Sportsman STOL Kit?

Post by Bhbackcountry »

gahorn wrote:
Bhbackcountry wrote:Thank you. That’s where I was looking too. I was hoping there was an approval floating around that I didn’t know about. I’m curious what the next step would be since it’s already installed or if it’s even worth continuing with the prebuy.
I would ask the last annual inspector how he approved that?

If you don’t get a basis of approval for it, you will own an airplane that’s is not approved for return to service. Move on.
That’s kind of what I was afraid of. I’m still wet behind the ears as far as this association goes but I see in the Document Library #146 is a 337 for a Sportsman Kit on a 170a. Does that mean there is or was an STC floating around for it too? I’m not very knowledgeable on the maintenance side of the house?
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DaveF
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Re: 170A with the Sportsman STOL Kit?

Post by DaveF »

Document 146 is partial documentation of a 1993 field approval for installation of the kit. Field approvals were fairly common 27 years ago, but not anymore. According to the documents, they even hired a DER test pilot to verify aircraft performance for FAA approval.

(Sorry if you already know this, but) a field approval is a one-of-a kind approval from the FAA to modify a single airplane. A Supplemental Type Certificate, on the other hand, is a general approval for many airplanes. In a field approval, a mechanic called his local FAA office and said, "hey, we want to modify this one specific airplane, and here's why we think it's ok. Tell us what we have to do." Could be something simple, like installation of a radio in an airplane that wasn't covered by an STC. Or it could be something more serious, like installation of a STOL kit.

It's possible that the airplane you're looking at was modified the same way, with a field approval. Or maybe there was a generally-available STC back in those days that no longer exists. Just because the Stene website doesn't list an STC for the 170A today doesn't say a thing about what might have been legally accomplished decades ago. Is there a Form 337 in the logs? What does it say?

You need to show the logs to a knowledgeable inspector to find out whether the mod is legally and properly installed. Be absolutely sure you get the right answer, because if you buy the airplane and it turns out the opinion is wrong, you could be in an expensive world of hurt.
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Bhbackcountry
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Re: 170A with the Sportsman STOL Kit?

Post by Bhbackcountry »

Thanks Dave. I didn’t scroll down far enough to see the narrative page but it makes sense now. I just received the info from the title search. The aircraft was mistakenly registered as a B model after the last purchase. They submitted a 337 for the installation of the Sportsman STOL Kit but referenced the Stene Aviation STC for a 170B. I’m not sure what or if anything can be done to rectify it but I’ll keep doing some research.
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n2582d
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Re: 170A with the Sportsman STOL Kit?

Post by n2582d »

AC 43-210A covers getting approval for major alterations. It would be nice if Stene could use that DER's flight test report/data referenced in document #146 as approved data to add the C-170A to the AML for the Sportsman STOL kit. ... when pigs fly. :(
Gary
hilltop170
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Re: 170A with the Sportsman STOL Kit?

Post by hilltop170 »

You can get the entire record of the aircraft that has been submitted to the FAA for a small fee (which may be different than the title search info) and it will be obvious if it had a field approval for the Sportsman mod.

You could also request the FAA records for the Document 146 aircraft which should/maybe will include the DER’s report used for the Field Approval. If you get the DER’s report, your IA should be able to use that info to get a Field Approval for your proposed plane. That info could also be sent to Willie Stene so he can use it to get the 170A on his AML.

Lots of maybes in there, good luck.
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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Bhbackcountry
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Re: 170A with the Sportsman STOL Kit?

Post by Bhbackcountry »

Just finished going through all the FAA records. I don’t see a field approval, just the 337 referencing the Stene Aviation STC. I found a post on the forum from 2015 from the owner prior to the current one. There’s even a picture of the kit uninstalled. Who knew that little kit could cause so many problems.

http://cessna170.org/forums/viewtopic.php?f=5&t=12390
hilltop170
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Re: 170A with the Sportsman STOL Kit?

Post by hilltop170 »

Look at the 337 and see if there is an FAA signature in Block 3. If there is, that is considered a Field Approval and your good to go.

If there is no signature in Block 3, that indicates it is a Major Modification authorized by the referenced STC. But since the 170A is not on the AML, it is not a valid authorization. Be sure and talk to Willie Stene, he is a great guy and might be able to help.

The seller’s IA could try to get a Field Approval based on the previous DER report, that would be the easiest method to use.

Otherwise, walk away if approval can’t be obtained. That’s a deal-breaker.
Last edited by hilltop170 on Sat Apr 04, 2020 2:42 pm, edited 3 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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Bhbackcountry
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Re: 170A with the Sportsman STOL Kit?

Post by Bhbackcountry »

hilltop170 wrote:Look at the 337 and see if there is an FAA signature in Block 3. If there is, that is considered a Field Approval.

If there is no signature in Block 3, that indicates it is only a Major Modification authorized by the referenced STC. But since the 170A is not on the AML, it is not a valid approval.

Your IA could try to get a Field Approval based on the previous DER report, that would be the easiest method to use.

There’s no signature in block 3 so I guess now I need to decide if this plane is worth the trouble. Has anyone done a field approval recently? I wonder how long that process takes?
hilltop170
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Re: 170A with the Sportsman STOL Kit?

Post by hilltop170 »

I have had them done all along, they can happen quickly or drag on forever, it depends on 1) the relationship the IA has with the FAA inspector, 2) the inspector’s latest directives from the FAA, 3) the mod itself.

There is really no reason the 170A should not be on the AML, it is a great mod and the wing is the same basic design as the 170B except for the flaps. Plus, supposedly there has already been a DER report on the installation which should be a good basis of approval if a copy could be found or the FAA inspector could be convinced based on the previous Field Approval. It’s worth a try.

GETTING A FIELD APPROVAL IS NOT YOUR RESPONSIBILITY, IT IS THE SELLER’S if the seller wants to sell the plane.

Nothing prevents you from buying it as-is but you will own a $$$ VERY EXPENSIVE $$$ problem at that point.

The plane is NOT legal like it is unless the seller can get approval.

If the seller cannot get approval, WALK AWAY!

Even if the Sportsman is removed, the wing will still be unairworthy due to the hundreds of rivet holes.

Check the data plate on the door post and see if the model and s/n matches the registration. That is another issue that needs to be resolved. The model number cannot be changed, once a C170A, always a C170A.
Last edited by hilltop170 on Sat Apr 04, 2020 2:45 pm, edited 1 time 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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Bhbackcountry
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Re: 170A with the Sportsman STOL Kit?

Post by Bhbackcountry »

This site is an incredible resource! Thank you for all of the info and suggestions. I’m going talk it over with the seller and see what he says.

Pat
Metal Master
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Re: 170A with the Sportsman STOL Kit?

Post by Metal Master »

Wille Stene was helpful sending me all of the material I needed to get a Field approval for the Sportsman leading edge for my 170A. There is a set of sample paperwork for a 170A that also had a Lycoming 180 HP engine installed in the members only pages on the associations home page. As my aircraft has a 210 HP TCM engine installed it was considered a similar installation. Because the original paper work that Willie provided me and a supplemental operators manual associated with it written by the DER that did the flight test data in the sample 170A for the original "one time" field approval. The FAA decided that mine needed to be a coordinated field approval with the ACO and FSDO. My principle FAA maintenance inspector managed the coordination with the Aircraft certification office. Ultimately because the 170B has no operators manual supplement for the Sportsman STOL, the ACO rep determined that an operator supplement was not required and authorized the FAA maintenance inspector to sign block 3 of the form 337. I got the field approval before I ever purchased the kit. I did all of this in 2018.
I purchased this from the association from the members only 337's and STC's section. = ___ 146 Stol, Sportsman (170A) . . . . . . . . . . . . . . .6.00. a good value for research. It was ultimately part of the same paperwork Willie sent to me via e-mail at no charge.
The ACO rep talked with Willie to ask why he has not had the 170A added to the approved model list. My understanding was that it is essentially low hanging fruit issue. Not enough 170A installations are sold to warrant the expense.
Jim
A&P, IA, New owner C170A N1208D, Have rebuilt some 50 aircraft. So many airplanes, So little time!
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