Prop cable bracket

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ateamer

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IMG_0489.jpegIMG_0496.jpegIMG_0499.jpegI have a Cessna 175 with a Lycoming O-360 and Hartzell prop (STC by Doyne/Williams/Avcon). The prop cable is not properly installed and I am trying to get the right bracket for it, but have struck out so far. The photos show the issue: Instead of being secured to the governor with a bracket, the prop cable sheath is clamped to a bracket which is bolted to the firewall. The bracket is roughly made, and pivots slightly, which alows the entire prop cable to move, leading to random RPM variations.

The logbooks have no entry for this bracket, and I doubt it conforms to the STC drawings. Unfortunately the drawings did not come with the plane, and the company does not return calls or emails. (My understanding is that it’s owned by an elderly couple and only really exists on paper.)

Anyone have suggestions for where to get a bracket? I tried one from Showplanes (RV items) but it does not mate with the governor. Can an A&P approve a shop-built bracket that attaches to the governor bolts?

I’m trying to get as much info as possible before calling my A&P and running the billing meter. This seems like something I should be able to do, aside from the regulations related to it being a certified aircraft.
 
Whoever did that does not understand how aircraft cables are mounted/secured. I am sure you know the bracket you speak about secures at that grove at the end of the outer cable.
What did they use for cable separation when new on a 175 before zip ties?
 
ateamer said:
Anyone have suggestions for where to get a bracket?
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Whats the STC number? As I recall this is not a rare problem with this STC. Perhaps post on a 175 forum or social media page for options. If no joy, send a certified letter to the current STCs holders address requesting the information. At the same time contact the certifying ACO listed on the STC document and let them know you can get no assistance with STC.

ateamer said:
Can an A&P approve a shop-built bracket that attaches to the governor bolts?
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No. But you can as an owner produced part. However, you'll need to know what the bracket looks like and dimensions. Then you can get that data approved. Its doable especially when an STC holder does not support the requests. However, I believe you might find a solution on a 175 type website.
 
Scuzzy setup, that. Really need to get the drawings. I'd bet that the cable isn't even the correct one.

Engine vibration will have the governor lever constantly rotating a tiny bit. Expect wear.
 
Not good.

You want to bracket on the Governor so the wear Dan mentioned doesn’t happen. Everything should move together. I need something like that for a
PA-12 throttle.

It may not stop there though. After you get the bracket you may find a longer cable is needed due to rerouting.

Off the shelf may be easiest. Consider Commanche, Mooney, etc.
That may be what the STC folks did.
 
To secure to the firewall? Get a piece of steel and make one. No STC worries. You just need to provide a secure and stable bracket.
 
Keep in mind that you don't have to make it yourself to qualify as an owner produced part. You just have to participate substantially. Providing the specifications and materials meets that requirement. So if you find drawings or an example to replicate, you can have it made from that.
 
Magman said:
It may not stop there though. After you get the bracket you may find a longer cable is needed due to rerouting.
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The bellcrank on the governor is indexable. The cable could be rerouted to come at it from the side rather than the rear, and the bracket could be attached to the accessory case studs or whatever other engine point is convenient.
Stewartb said:
To secure to the firewall? Get a piece of steel and make one. No STC worries. You just need to provide a secure and stable bracket.
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The cable's housing should be attached to the engine or governor, and move with it. One never sees a certified ship with controls anchored to the firewall. Engine movement would cause wear to the control and to whatever it is controlling.
 
Sure thing. Keep all the adel clamps. Making a finger bracket at the engine side is simple. I can’t believe that mess made it through annual and got returned to service.
 
Stewartb said:
I can’t believe that mess made it through annual and got returned to service.
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I can, almost. I have seen some horrific stuff and the damage that results from it. Mechanics seem to forget that the engine moves, sometimes a lot. I asked the owner of a 172 to watch his uncowled Dynafocal-mounted Lycoming when I started and stopped it. He was flabbergasted at how much it shook. He was wondering why I had spent time (his money) to change some of the cable, hose and wire anchor points on it. No more argument after he saw that engine twist around.
 
Dan Thomas said:
I can, almost. I have seen some horrific stuff and the damage that results from it. Mechanics seem to forget that the engine moves, sometimes a lot. I asked the owner of a 172 to watch his uncowled Dynafocal-mounted Lycoming when I started and stopped it. He was flabbergasted at how much it shook. He was wondering why I had spent time (his money) to change some of the cable, hose and wire anchor points on it. No more argument after he saw that engine twist around.
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This reminds me of...
I dynamically balanced my buddy's prop on his old PA28-140. It made a world of difference especially starting up. He was really surprised and pleased. I have never seen a engine twist up like that.
 
Dan Thomas said:
I can, almost. I have seen some horrific stuff and the damage that results from it. Mechanics seem to forget that the engine moves, sometimes a lot. I asked the owner of a 172 to watch his uncowled Dynafocal-mounted Lycoming when I started and stopped it. He was flabbergasted at how much it shook. He was wondering why I had spent time (his money) to change some of the cable, hose and wire anchor points on it. No more argument after he saw that engine twist around.
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My annual a few weeks ago included 1-1/2 hours to repair an intake stud. I asked about what led to that. My mechanic recognized space behind a nut and tried to tighten it but found resistance. He removed it and found the nut was cross threaded. That nut had been untouched for 20 years. This shop has now done two annuals for me. He was ****ed that he missed it last year. I like thorough mechanics.
 
Bell206 said:
Whats the STC number? As I recall this is not a rare problem with this STC. Perhaps post on a 175 forum or social media page for options. If no joy, send a certified letter to the current STCs holders address requesting the information. At the same time contact the certifying ACO listed on the STC document and let them know you can get no assistance with STC.


No. But you can as an owner produced part. However, you'll need to know what the bracket looks like and dimensions. Then you can get that data approved. Its doable especially when an STC holder does not support the requests. However, I believe you might find a solution on a 175 type website.
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STC SA424CE

I have an email in to the Wichita ACO, which is where the original STC was approved through. I might have located a used original bracket, but it’s not yet assured.

I really believe that for an aircraft so long out of production (last one was 61 years ago), owners should be granted more leeway with regards to parts replacement. I understand owner-prodcued parts, but without the data on dimensions and such, it’s useless in this situation.
 
ateamer said:
I really believe that for an aircraft so long out of production (last one was 61 years ago), owners should be granted more leeway with regards to parts replacement.
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Except there have been alternatives to part replacements for years. You just need a willing mechanic to pursue them. Same with owner parts. You wouldn't be the 1st person to have an ACO engineer pull a drawing copy of an unsupported STC, send it out, then have the owner produce one legally. Nor would you be the 1st to replace that bracket as an alteration. But yes, you at least need a picture or drawing to see what the original bracket actually provided. And just to add, its better to call the ACO than send emails as there have been a few reorganizations since the 70s and you can get to the correct person quicker by calling than email.
 
Bell206 said:
Except there have been alternatives to part replacements for years. You just need a willing mechanic to pursue them. Same with owner parts. You wouldn't be the 1st person to have an ACO engineer pull a drawing copy of an unsupported STC, send it out, then have the owner produce one legally. Nor would you be the 1st to replace that bracket as an alteration. But yes, you at least need a picture or drawing to see what the original bracket actually provided. And just to add, its better to call the ACO than send emails as there have been a few reorganizations since the 70s and you can get to the correct person quicker by calling than email.
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I’ll call them.

Thank you so much for the advice!
 
Well, this just came in from the FAA:

The Central Certification Branch received your inquiry requesting information concerning the STC SA424CE, and the owner, Bob & Barbara Williams.

The Williams' are alive and well, and protect their STC data zealously. All support documents, such as the MDL, AFMS, ICA, installation instructions, and drawings, etc., are considered proprietary data. The FAA is not allowed to give you this information.

I understand that you emailed Mr. Williams as directed and he has not responded. Mr./Mrs. Williams’ are in their 90’s, and they do things at their leisure or not at all. If the Williams' decline to support this STC, the FAA cannot make them support it. And the support documentation will remain unavailable.

The only other solution I can offer you is to search for other people who already purchased the rights to the same STC, and may still have the pertinent data. And/or keep trying the Williams’ email address. They only respond to email.
 
Yeah, so at this point if the one bracket I might have located works out, I’m stuck with status quo. Or invoking FAR 43.69 - Orphaned Parts Replacement/Repair By The Hangar Fairy.
 
ateamer said:
Yeah, so at this point if the one bracket I might have located works out, I’m stuck with status quo. Or invoking FAR 43.69 - Orphaned Parts Replacement/Repair By The Hangar Fairy.
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The setup you have is not at all acceptable. It does not conform to the STC, I am sure. The FAA would never approve something like that.
 
ateamer said:
Well, this just came in from the FAA:
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Never seen an official reply like that before. Looks more AI generated than anything else. Whats interesting this office knows the exacting details of this obscure STC out of 50,000 STCs on the books. Any chance you can screenshot that reply and post it minus your info?

But if the STC has been “orphaned,” why not correct the governor cable as an alteration? If your APIA thinks it’s a major, work out how it will done on Block 8 of a 337 and take it to the local FSDO for a field approval explaining how the STC holders refuse to support the install. Regardless, I’d still make an extra effort on the 175 type sites as I recall this is not a rare issue.

I’d also submit a written request to the Certification head-shed to declare the STC abandoned by the holder and request the applicable engineering data as allowed by law be forwarded to you for any future issues.
 
Field approval. Just build one, have faa look it over and sign off.
 
Have a mechanic fabricate and install suitable brackets using standard practices. Log them as minor alterations, which they are. It’s an airworthiness issue and simple to fix.
 
Ran across this engine today from a Cessna 177 Cardinal. Maybe you could fabricate something similar?

PXL_20250814_223219898.jpgPXL_20250814_223241698.jpgPXL_20250814_223233760.jpgPXL_20250814_223229122.jpgPXL_20250814_223257051.jpg
 
"Ran across this engine today from a Cessna 177 Cardinal. Maybe you could fabricate something similar?"

Careful - The weird complexity of that part looks like a future AD waiting to happen.......
 
nrpetersen said:
"Ran across this engine today from a Cessna 177 Cardinal. Maybe you could fabricate something similar?"

Careful - The weird complexity of that part looks like a future AD waiting to happen.......
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It looks to have been patched, which makes it look complicated.

1755364404490.png

The section on the right, where the cable housing is connected, is original. On the left is a new section, held to the old by four bolts and anchor nuts, where a few rivets would have worked just as well.

There is no fore-and-aft bracing other than a hose clamp holding a tab against the governor body, leading me to think that the old one flexed under vibration and broke at the narrow sections at the governor. The tab is part of the new section and might be an attempt to stabilize the bracket.
 
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