Doyn O-360-A1D engine conversion -- need drawings

[LakeHood170B]

Thanks, everybody, for your inputs. I've been in SEA for the winter and will be going back up to ANC where the a/c is within the next few weeks and be able to look at things instead of relying on photos I took last season.

I heard this week from a guy in BC who says he has a 170 Doyn conversion, and is looking for drawings in his records.

BTW, my a/c does have an electric fuel pump, even though it's a B (1952) model.

I have not received any response to the voicemail message I left in Udall KS -- I'm not surprised given the past posts I've read.

[Indopilot]

H Mark Smith talks about Standardization in his post. I think I was told pretty much the opposite from what you were told George, from our FSDO.
We have a 206 with a mod and no installation instructions made it to us when we got the plane. In talking to my PMI he said to contact the region from which the STC originated and they would have a copy of the info we need.
Secondly I bought an 180 Lyc STC from a wrecked 170B for our 171 after talking to and recieving from my PMI a 337 stamped approved. He said the FAA didn't care that the STC had been on another plane as long as you had aquired the STC legally and were not just copying paperwork to make up your own. In other words making sure that the STC owner at one time had been compensated for that STC. Brian

[GAHorn]

H Mark Smith talks about Standardization in his post. I think I was told pretty much the opposite from what you were told George, from our FSDO.
We have a 206 with a mod and no installation instructions made it to us when we got the plane. In talking to my PMI he said to contact the region from which the STC originated and they would have a copy of the info we need.
Secondly I bought an 180 Lyc STC from a wrecked 170B for our 171 after talking to and recieving from my PMI a 337 stamped approved. He said the FAA didn't care that the STC had been on another plane as long as you had aquired the STC legally and were not just copying paperwork to make up your own. In other words making sure that the STC owner at one time had been compensated for that STC. Brian

I certainly wouldn't want to "put words" in the mouth of the FAA... but there's a difference in what you are describing, and what the FSDO in my region (and I suspect, yours also) is describing.
In the case of your 206, the region in which the STC originated may indeed have an original copy of engineering data, drawings, instructions, etc., of the STC application...however they will not provide you with a copy of them. This is because the owner of that STC has proprietary rights to that data and it's approval. (Likewise, some STC's, due to simplicity or other obvious basis, may gain approval from a FSDO without that office retaining any copies of the data/instructions, etc.) In neither case will any FSDO provide you with a free copy of the STC.
If your airplane was so-modifed, and if the original STC holder were no longer able to be found, then a FSDO might allow you to have maintenance instructions for continued airworthiness, if any existed in their possession. But they'd have to be convinced that 1- the STC holder was not able to be located and 2- the modified airplane had legal rights to the data by having acquired the STC legally. Unless there were obvious clues to the contrary, the FSDO will assume that an owner's claim to have legal possession of the STC is valid. The document they'd likely rely upon will be the aircraft logs and Form 337. (The FAA is not knowingly going to become complicit in assisting someone to operate an airplane that has been illegally modified.)
If, on the other hand, their research found the STC holder, and if he claimed no record of the aircraft serial number having acquired that STC thru him existed, then the airplane would likely be grounded until the modification were removed and/or the airplane otherwise returned to airworthiness. The legal issues arising from that instance would be separate, as regards the STC holder. But the legal issues with regard to the owner's operation of that illegally modified airplane would fall under the purview of the FAA.
In the case of a 170 for which had the STC had been purchased and installed and subsequently wrecked....that STC was applicable ONLY to that original airplane's serial number. It may not be transferred to another aircraft serial number without the approval of the STC owner. Unless that STC owner agreed to allow that transferance from one serial to another, the mere purchase of documents from another owner does not qualify one to modify another serial airplane. Nor does it allow the purchase of the salvaged parts from the first airframe for installation upon a different airframe, without approval of the STC holder. (You can't simply go to the junkyard and buy a spin-on oil filter that was STC'd for the wrecked airplane, and install it on another airplane...not even if the wrecked airplane's maintenance records were also acquired. The STC must be licensed to the individual airframe. Nor can I, owner of two 170's, buy one STC and install it on two 170's. Neither can I install it on one 170, then later transfer to to the other 170, without the STC holder's agreement and re-issuance of STC.)
When your IA modifies your airplane and submits a Form 337 stating he has modified your airplane in accordance with STC 1234567, and the FAA receives that Form,...they may or may not research to see if the named STC actually is applicable to your airframe. The assumption is given that your IA did the modification legally: Meaning that the STC was purchased/acquired legally either from the STC-holder or his agent, and that the work was performed per the instructions using the approved parts. If it turns out that such is not the case, then the owner (you) is also accountable because the owner is responsible under the FARs for the airworthiness of the airplane. If the IA knows about the deception, he is also liable, just as you both would be if the IA is the person who sold you that modification illegally (because he went to the junkyard, got the parts, and handed you the improper paperwork), even if you knew nothing about the deceptive maintenance. Be careful who you let work on your airplane.
The FAA doesn't go around calling STC owners to see if every airplane in the field paid them for the mods. They assume that since the STC owner is in business to sell his product, that he knows how to conduct his business. (And the laws of the land already know how to deal with fraud.)
The FAA will take a serious interest in the illegally modified airplane however, when a subsequent IA looks at that plane and denies it approval for return to service after annual inspection, and reports it to the FSDO. (Meanwhile, if you carry insurance on your airplane to protect yourself from accidental loss, you might save your possibly-wasted premiums.)

[blueldr]

Don't we have any Philadelphia Lawyers that can chime in on this thread?

[GAHorn]

I prefer to believe that most people are honest and want to operate their airplanes legally, and do not intend to "pilfer" the work product of others.
If it seems silly that we should pay for the things we didn't invent, develop, and obtain approval for ourselves, then the point is missed, indeed, whether one is in Philadelphia or anywhere else.

John, in response to your comment, I should have mentioned that it's not the FAA's job to make sure the "STC owner was at one time paid for the STC" or not. (The STC owner must be paid EACH time his STC is used, not just ONE time or SOME times. etc., but it's not the FAA's job to enforce laws of commerce.) It's their job to see that the airplane maintains a basis of airworthiness and that instructions for continued airworthiness is followed, and it's the aircraft owner's job to legally acquire that data from the STC owner.
Similarly, the FAA cannot legally hand out the property of the owner by giving away copies (if they have one) to people who claim to already own the product. That'd be like the patent office giving out the secret formula for a product, just because we bought one (or claimed we did.) There is no legal way around it that I know of. If you claim to have modified your airplane in accordance with an STC, you'd best have paid the STC owner for it. If you own an airplane modified in accordance with an STC, you'd best have an authorized copy of that STC. It's similar to having a computer with pirated software in it, except that it's a lot more serious (and easier to get caught and/or worse.)

[c170b53]

I'm trying to hold back George and I will, as I think its one of those threads. Lets remember on thing, the age of our aircraft and the changing regulations. Instructions for continued airworthiness, is an example of a requirement brought about by MSG philosophy, an invention of late 60's. The requirement of new STC's, replacement parts and paperwork has changed to deal with the new regulations. I'm not so sure that todays process can dictate what had occurred years ago. In other words, I believe that an old STC embodied in an aircraft, could be used in a subsequent aircraft if the original requirements of the STC were met.

[Indopilot]

George you seem to be slowing down so better stir the pot again. At another IA seminar the subject of STC was brought up, and it was pointed out that the STC holders who marked " FOR S/N 123goofy ONLY " across the front of the STC were actually Illegally marking a closed FAA approved document by adding something that was not there when the FAA approved the STC.
I agree that if the STC people sell 100 stc's there should only be 100 of that stc out there. Not 101 or more. I don't agree that they should be able to sell 100 stc's 101 or more times. That would be like buying a wrecked car with fluffy dice and then having to pay Walmart for the fluffy dice again before installing them in your car.
And again I was just passing on what I have been told by the FAA Brian

[GAHorn]

STC's should be thought of as copyrights without time limits. If you have a professional photographer take photos of your daughter's wedding, and you want copies of the photos, ... you must pay for them. If someone else wants copies....they must pay for them. As long as the copyright remains valid, if 20 years down the road you want more copies...you must pay for them. You may not (legally) make copies of them on your own. Their copyright is owned by the photographer... unless you buy the copyrights to the photos from him.
Keep in mind that STC stands for "Supplemental Type Certificate". They have no expiration dates. (Good thing. It'd be a shame if the STC on your airplane expired last year and the owner couldn't be found. You'd have to remove the mod, or find another basis of approval.)
If the original Type Certificate still belongs to someone, say for example - Cessna, ... and if that Type Certificate is still valid (and it is unless the FAA revokes it)... then you can still operate your Cessna 170 based upon that airworthiness data and Type Design as long as your airplane receives an annual inspection that determines it meets the Type Certificate Data.
If the original Type Design is changed in such a way that the airplane no longer meets it's original Type Certificate Data, ... then the airplane must have a different basis of approval for airworthiness. Several ways to do that exist: 1- New Type Certificate 2- Supplemental Type Certificate 3- "Field" Approval (a form of one-time STC issued by the FAA inspector based upon his own assessment.) None of them have expiration dates.
An airplane altered in accordance with an STC is always subject to the STC (and it's limitations, if any) unless that modification is removed. The only source for obtaining the STC is the STC owner (or his agent.) Time does not change that requirement. If the STC owner cannot be found, then the STC cannot be purchased and if that exact same modification is applied to an airplane.... another basis of approval must be obtained. Finding one in a junkyard, or photocopying someone's copy of that STC paperwork does not qualify (except in the rare case of a STC donated to "public domain" such as the original EAA autogas STC.) Either a Field Approval, or another STC must be purchased from some other STC-owner who also STC'd the modification. (Example: lots of 180 Lycoming STC's exist. While they may have minor differences between them, there is more than one source for such a STC. Or... you can go to the trouble and expense to apply for one yourself and be an STC owner,...if you want the liability you can sell that to someone else.)

My airplane had been re-imported into the US from South America with the incorrect engine on it. It did not have the Type Certificated C-124-2, or O-300-A,.... instead it had an O-300-C (which due to that engine's 6-bolt prop flange, also had a propeller on it which did not meet the original Type Certificate... it had a McCauley EM-7655 prop. This engine/prop combination was approved on later 172's, but was never approved by the 170 Type Certificate.)
When the airplane was re-imported, it had to undergo a "conformity inspection" in order to determine it met it's original Type Certificate before it could be issued a U.S. Airworthiness Certificate. The inspector (a genuine FAA Inspector) boo-booed and issued the Airworthiness Certificate, because either he didn't know the difference, or he simply missed the fact that the incorrect engine and prop was on the airplane. It flew that way for 30 years.
I was told by many "experts" that I should keep my mouth shut and keep on flying. The most common argument was, that since the FAA themselves issued the Airworthiness Certificate, even though they issued it in error, that since it was they themselves who did so, it was now "approved data" and they could not change their minds about it.... my airplane was "good to go" forever.
That is not correct. Unless a basis of approval was found to provide airworthiness for my modified airplane, that my airplane was flying in an altered state that did not meet it's Type Design, and that anytime some Inspector noticed, he could/would/SHOULD deny re-licensing of the airplane during annual inspection/inspection and when the FAA discovered their error they would revoke it and require me to mail the Airworthiness Certificate back to the FAA.
If the airplane crashed due to an engine/propellor failure, etc., my insurance company would have a good case in court to deny payment for loss of the airplane. I was wasting my money buying insurance. In fact, although I'd had an annual inspection performed as part of my pre-purchase inspection, ... that annual inspection was performed incorrectly when it did not correct the problem way back then. (I actually did notice the difference, but I fell for the common mis-conception that this discussion thread is addressing: Namely, that simply having a Form 337 completed that was based upon and referred to another airplane's Form 337 which had been "Field Approved" by the FAA was sufficient to make my airplane airworthy as well. My airplane's records included a Form 337 from another 170B that had been approved in Block 3 (Field approval), and my airplane's records also had a Form 337 with referenced that other Field Approval. It looked legal.
But it ain't so. MY airplane must have it's OWN Form 337 Block 3 approved by the FAA. It would also have to undergo it's own Field Approval (although the FAA might accept the other airplane's Form 337 as "acceptable data".)
Since Change 15 regarding Field approvals occurred a couple years ago, and since that Change greatly complicated the obtaining of Field approvals, I knew this would be a difficult process. I would have to provide engineering data, etc., etc., and it was going to cost me a lot of time and money, and meantime... my airplane was actually illegal! It had been flying illegally for 30 years!
(Not talking about safety of flight... but talking about legalities here.)
I decided to bite-the bullet and correct my airplane's illegality. Fortunately I found a very simple solution: Obtain a legal copy of the STC which approves the installation of this engine/prop on a 170 from former TIC170A president Ron Massicot ! ( Ron has a very simple and painless method to "sell" you his STC: Be a TIC170A member and pay TIC170A $75 for it. If you are one of those folks who have the later engine, either a O-300-C or -D engine, and the EM series prop, ... or if your engine has had a later 6-bolt crankshaft installed and the EM series prop, ... this is the way to go.)
Ron then sent me a legal copy of the STC paperwork that made my airplane legally airworthy with the modification. I sleep better now. I also don't worry about flying my airplane someplace for a hamburger and then returning to it to find a grounding "Condition Tag" on it, issued by the local FAA guy who happened to notice an illegal modification.

The marking of the STC by the owner of that STC with the serial number of the aircraft to which it is being issued does not constitute an "illegal" or alteration to the document or it's data. (It's not a change of either the data or the FAA's acceptance of that data, and it is no different than the identification-legend across the top of a Faxed document. It's the DATA that the FAA accepted and approved. The USE of that approved data is what is in question here. The document supplied by the STC-owner to the purchaser is merely being identified by the seller as a legitimate copy that has been legitimately acquired.) It actually simplifies matters for the purchaser, in that it identifies the airframe to which the STC is intended, and removes any doubt in the future as to whether that STC was legally issued to the airplane.

[Indopilot]

Just courious George, what is the source of your info? If it is the FAA, this post is a good argument for standarization in the FAA like H Mark Smith was talking about.
I suppose we could have a face off of your FAA guy against mine. That would be a switch, rooting FOR the FAA. Maybe we could sell tickets and half the proceeds go to the Association and we could split the rest. Of course there would have to be rules. It would have to be the guy you actually talked to, fairly close in age, no bantam weight against a heavy weight, that sort of thing. They would be allowed bring their own paperwork. If we can't find impartal judges we might have to call it off. Brian

[GAHorn]

Ha! Yes, Brian, it is a problem when one FAA Inspector contradicts another FAA Inspector. The Inspector in the region having jurisdiction over the airplane (either where it's based, or where the modification is being performed) is the authority to whom one should look when a question arises.
These differences of opinion by Inspectors is an age-old problem, and "standardization" is exactly why the FAA recently made changes to the process of Field Approvals (which irritated everyone who would like to expect the process to remain simple and local.) Unfortunately, it's that "standardization" that has so many "up in arms". Standardizing airworthiness issues has caused the FAA to re-evaluate the methods by which individual Inspectors in different regions have signed off on "Block 3". There's been little coordination between regions, and in some cases there's been little, if any, engineering data or other basis to support some Field Approvals. On top of all that, there's been little or no actual description of exactly HOW some mods have been accomplished. This has led to other Inspectors approving some mods that actually had nothing in common with another, accepted mod, other than the name by which it was called. This has led to lots of airplanes being modified in unairworthy manners, yet received approvals simply because another airplane somewhere in the world had a similar mod performed, but had not documented the methods used. (If I install a gizmo, and get it approved, ...and then you install a gizmo and show where mine was approved,.... and then an Inspector approves YOUR gizmo installation simply because MY Inspector approved MY gizmo.... overlooks the fact that in order to make MINE airworthy, it had to be installed using only 25.75 inch-lbs of torque. If my Form 337 didn't specify that...then how would YOU know it? How would your Inspector know it? You wouldn't.
But lots of gizmos were being installed using all different torques, and some of them were installed using super-glue!..... but they all were being approved. The FAA has decided to standardize things. They already know the problem.
The public just doesn't like to see things change. A lot of people would like to just mod the airplane, and go on down the road without any more hassle about it. Unfortunately, that doesn't guarantee airworthiness.

[echomike]

[quote="blueldr"]I believe that those engine conversions that required an electric fuel pump on conversions utilizing a carbureted engine were predicated on the basis of horse power versus fuel line size, similar to the situation on the
C-170 which required the engine driven pump. Installing an electric boost pump was easier than re-piping the fuel system to larger size. The C-170 inherited its fuel system from the C-140 but due to the fuel line size it was required to have a fuel pump. In the C-170A and C-170B they increased the fuel line size and the fuel pump was no longer required for certification.[/quote]

My understanding of the 170 fuel system requiring an engine driven or electric boost pump was that there was an option of:
1) A lengthy "documented-read 337" engine run + flight test required
(at several different aircraft attitudes and power settings).
2) Re-piping the fuel system.
3) Install an engine driven fuel pump and lines to carb.
4) Install an electric boost pump and lines to carb.

Sucessfull completion of any of the options met the requirments of the AD.

My 1948 C-170 (ex ragwing) has the documentation showing the sucessfull completion of option #1, and has never had an electric or engine driven fuel pump installed. Still flies great after 58 years.

OK, Let the opinion storm begin. Hi George, probably see you at Reklaw this year... Fly Safe, EchoMike

[LakeHood170B]

I've contacted the FAA Wichita ACO about this. The receptionist indicated that I'm not the first person seeking into about this STC b/c of the STC holder being unresponsive. I was directed to leave voicemail for the FAAer who is directly looking into this matter and did so. Hopefully I'll hear back from him. I think this is progress!

[lawson]

Hi-
I just acquired the blueprints for my Cessna 170a(Lycoming O-360-A1A)...i got them from Bob Williams at Avcon, Udall, Kansas. I would keep trying him. He was friendly on the phone, and (although it took several attempts of calling him-he's not super good about returning calls)....he did send out the blueprints within a few days. Good Luck.

[LakeHood170B]

I started this thread over a year ago. I still have been unable to obtain any data regarding the Doyn conversion on my 170B. FAA has tried to contact the STC holder on my behalf without success, even telling me that they cancelled some of the party's PMAs years ago for failure to respond to FAA's own inquiries.

I guess I can live with just the one-page STC I find on faa.gov and my 337, HOWEVER, now my tach has crapped out and I need to buy a new one and have it painted with correct range markings. The now-dead tach is a bit strange, with the following markings:

2000 t0 2200 RED
about 2250 or so to 2700 GREEN
2700 REDLNE
Note the gap between the red and green.

Can anybody tell me what the proper range markings are for the tach? I suspect they would be the same for the Doyn conversion as for the Avcon, so Avcon airplane owners are encouraged to respond. I'm sure my IA will accept Avcon ranges in lieu of Doyn.

[jon s blocker]

I think there is/ was a vibration resonance problem with that engine at the listed red line, but up to 2250. I believe that was the range in which you were not to use that RPM to cruise at. Hartzell did away with that when you use their dampener, (this is used with their 80" prop STC). I don't have a copy of the Doyn conversion, but that was a common restriction with most of the conversions with that engine/airframe combination. I have the Delair STC,and with my Prop STC that restriction is done away with. I will check the RPM range on the paperwork I have and check the old RPM restrictions on it, I bet it would match up. Rememeber though, I'm not the FAA. Jon