Polishing prop

[Tom-D]

OBTW we in the Field as A&Ps are not allowed to make repairs to props, all we are allowed to do is minor maintenance. So when we don't make repairs, we don't replace the finish.

Blending leading edge damage isn't a repair?

How do you explain the above STC which is clearly for an alteration? Can you alter the prop?

You can always apply any STC that applies. That's a completely different issue than polishing a prop.

Repairing minor Discrepancies is of course maintenance and requires a return to service entry in the proper log, But that isn't the issue I presented to Ron, he is contending that when you blend a prop you must return the finish to the original condition. That is simply untrue.

 

[Silvaire]

Are you stating the the widely publicized prohibition on polishing props that came about around 20 some years ago, holds no merit in fact with regards to legal prohibition?

I'm sorry Henning but Googling "widely publicized prohibition on polishing props" produces nothing other than a link to your own post. You'll have to give me something more than that to work with. For one thing - publicized by who? Polishing props goes way back and it certainly didn't suddenly stop 20 years ago.

 

[Henning]

I'm sorry Henning but Googling "widely publicized prohibition on polishing props" produces nothing other than a link to your own post. You'll have to give me something more than that to work with. For one thing - publicized by who? Polishing props goes way back and it certainly didn't suddenly stop 20 years ago.

Prior to about 20 years ago, there were polished props all over the bloody place and nobody seemed to give a flying ****, then suddenly a giant kerfuffle arose and that ended with condemned and repainted props across the country, which is the subject base for this part of the thread. There were 3 planes on the field that I was working on at the time that were affected, one had to replace his prop, the other two got painted. I'm wondering where that came from.

 

[Stewartb]

A few years ago I asked for and received a field approval for installing landing and taxi lights on the gear of my PA-12. I used NAPA rubber housings and aviation bulbs, did the electrical calcs, etc. The only thing that FSDO seemed interested in was potential reflection off the prop and in fact they required me to add ICA language that any prop installed must be maintained in a non-reflective black finish.

 

[poadeleted20]

BS show it to me in writing

Look back up this thread -- the ICA for the OP's prop is linked, and 43.13(a) should be well-known to you.

 

[bnt83]

A few years ago I asked for and received a field approval for installing landing and taxi lights on the gear of my PA-12. I used NAPA rubber housings and aviation bulbs, did the electrical calcs, etc. The only thing that FSDO seemed interested in was potential reflection off the prop and in fact they required me to add ICA language that any prop installed must be maintained in a non-reflective black finish.

My old old Cessna 150B was polished and the blade faces were flat black like any other. I was ramp checked one day goofing off at my home base of Springfield SD. This was ?1999-2000? before I even held a PPL or A&P. That airplane wasn't in the best of shape either. Nothing came of said ramp inspection. You can imagine their wide open eyes when they stumbled across a high school kid dinking around a doggy looking Cessna 150 all alone and only a student certificate.

All the pictures I can see online by googling the registration # looks like it is still polished.

 

[nrpetersen]

FWIW - From somewhere I've seen from lab fatigue coupon tests that surface anodizing reduces the allowable stress of 2024 T3 aluminum about 10% when compared to polished.

 

[Tom-D]

Look back up this thread -- the ICA for the OP's prop is linked, and 43.13(a) should be well-known to you.

I did ,, and there is nothing in your manual that supports your contention.

FAR 43.13
(a) Each person performing maintenance, alteration, or preventive maintenance on an aircraft, engine, propeller, or appliance shall use the methods, techniques, and practices prescribed in the current manufacturer's maintenance manual or Instructions for Continued Airworthiness prepared by its manufacturer, or other methods, techniques, and practices acceptable to the Administrator, except as noted in §43.16. He shall use the tools, equipment, and test apparatus necessary to assure completion of the work in accordance with accepted industry practices. If special equipment or test apparatus is recommended by the manufacturer involved, he must use that equipment or apparatus or its equivalent acceptable to the Administrator.
end quote

Even using that, there is nothing in your ICAs that require the paint to stay on the blades, nor any statement saying I must return the prop to its new condition.

 

[poadeleted20]

I did ,, and there is nothing in your manual that supports your contention.

FAR 43.13
(a) Each person performing maintenance, alteration, or preventive maintenance on an aircraft, engine, propeller, or appliance shall use the methods, techniques, and practices prescribed in the current manufacturer's maintenance manual or Instructions for Continued Airworthiness prepared by its manufacturer, or other methods, techniques, and practices acceptable to the Administrator, except as noted in §43.16. He shall use the tools, equipment, and test apparatus necessary to assure completion of the work in accordance with accepted industry practices. If special equipment or test apparatus is recommended by the manufacturer involved, he must use that equipment or apparatus or its equivalent acceptable to the Administrator.
end quote

You must have missed the highlighted part.

Even using that, there is nothing in your ICAs that require the paint to stay on the blades, nor any statement saying I must return the prop to its new condition.

Agreed, but that's not what the discussion is about. The ICA's for the OP's prop do require that when a mechanic polishes the prop as part of a repair, it be re-coated when done. Unless you have some document which says that leaving the prop without a protective coating is "acceptable to the Administrator" in spite of what the ICA's for this prop under discussion say. And there's nothing in the ICA's authorizing anyone to remove that protective coating.

 

[Henning]

You must have missed the highlighted part.

Agreed, but that's not what the discussion is about. The ICA's for the OP's prop do require that when a mechanic polishes the prop as part of a repair, it be re-coated when done. Unless you have some document which says that leaving the prop without a protective coating is "acceptable to the Administrator" in spite of what the ICA's for this prop under discussion say. And there's nothing in the ICA's authorizing anyone to remove that protective coating.

What the A&P is doing with a file or abrasive is not a repair, it is maintenance. When a prop shop welds up the divot from the maintenance (or excessive damage directly) and gets it back to spec, that is a repair.

That is when it gets repainted.

The removing of the coating is not addressed because it is defacto in the wear and tear regardless of damage. It's unavoidable in normal operations.

 

[bnt83]

What the A&P is doing with a file or abrasive is not a repair

 

[Tom-D]

You must have missed the highlighted part.

No I understand what my responsibilities are when doing repairs, What you misunderstand is there is no statement that any A&P must use the ICAs as a return to service reference.

Agreed, but that's not what the discussion is about. The ICA's for the OP's prop do require that when a mechanic polishes the prop as part of a repair, it be re-coated when done.

No it does not. read it again, while you are at it, tell us why you believe these ICAs apply to all props, and why you believe they must be complied with in this scenario.

 

[bnt83]

 

[Tom-D]

Does any one see any statement in these ICAs that make them mandatory for part 91?

http://www.mccauley.textron.com/MPC26OWrev2.pdf

These are instructions to do the maintenance of the props in the application charts. IF and WHEN the need arises to repair the propeller.

There is no statement in these instructions that make the top coat/paint a requirement to stay in place.
Ron makes the mistake that the stripping and polishing of a propeller a repair, It isn't.

Do not interpret that I advocate polishing props, I simply say polishing one does not make it un-airworthy.

 

[bnt83]

Here is what McCauley said about polishing a 1A170 (aluminum fixed pitch McCauley prop):

Brian,

Hello. McCauley does not recommend polishing a propeller or removing the protective paint coatings. The drawings to which the propeller are conformed specify paint coating. While it may not be illegal, a grey area, we highly recommend not polishing a McCauley propeller and there are no instructions to do so.


If you'd like the email forwarded to you PM me.

 

[KRyan]

Hartzell specifically bans polishing their props.

 

[Henning]

Hartzell specifically bans polishing their props.

IIRC, it was a Hartzel that was condemned and had to be replaced and McCauleys had to be etched and painted. I think it was the Senseniches that could stay polished. It was an FAA guy that came to the field and brought it all up BTW, so there was definitely something at the FAA that came up about it because he put stickers on the affected planes and came in the shop to explain that those props were not in compliance, and Hartzel didn't have a procedure for bringing a polished prop into compliance, they said, "It needs to be replaced."

 

[bnt83]

"It needs to be replaced."

That's their #1 answer for most anything isn't it?

 

[Henning]

That's their #1 answer for most anything isn't it?

The day TRW finalized acquisition of Hartzel, an AD was issued IIRC. Hartzel props have become the BE-18 of props at collecting ADs since. They sure have sold a lot of Top Props and Scimitars since though.

 

[RotorAndWing]

What the A&P is doing with a file or abrasive is not a repair, .

 

[Henning]

That's the argument currently in play. There has to be a reason that the entire industry operates quite smoothly with a fleet of planes where at least 70% of props have the paint eroded off the leading edges, many by a mechanic dressing and leaving them in that condition. There has to be a principle, besides non enforcement, that allows this condition to exist in light of the wording of the ICA.

Would you care to enlighten us with the official FAA interpretation of why they don't enforce that all props maintain a perfect paint job?

Or is your sole capability in this matter copy any pasting GIFs?

 

[RotorAndWing]

That's the argument currently in play. There has to be a reason that the entire industry operates quite smoothly with a fleet of planes where at least 70% of props have the paint eroded off the leading edges, many by a mechanic dressing and leaving them in that condition. There has to be a principle, besides non enforcement, that allows this condition to exist in light of the wording of the ICA.

Would you care to enlighten us with the official FAA interpretation of why they don't enforce that all props maintain a perfect paint job?

I was replying to the ignorant statement:

Originally Posted by Henning
What the A&P is doing with a file or abrasive is not a repair, .

which AC 20-37E clearly defines as a repair.

 

[Henning]

I was replying to the ignorant statement:

which AC 20-37E clearly defines as a repair.

Ok, so where is the industry typical accepted line/standard drawn to repaint on repair at the prop shop, or whenever it is the owner decides they want to pretty up their prop, coming from? It's obviously there and accepted, so where is it defined to satisfy Ron? Is it the difference between minor and major repair? Because unfortunately, the documentation doesn't all specify a difference.

 

[RotorAndWing]

Ok, so where is the industry typical accepted line/standard drawn to repaint on repair at the prop shop, or whenever it is the owner decides they want to pretty up their prop, coming from? It's obviously there and accepted, so where is it defined to satisfy Ron? Is it the difference between minor and major repair? Because unfortunately, the documentation doesn't all specify a difference.

Go read AC 20-37E.

 

[poadeleted20]

Does any one see any statement in these ICAs that make them mandatory for part 91?

It's not anything in the ICA's which make them mandatory, since they are written by the manufacturer, not the FA. It's 14 CFR 43.13(a) which makes the manufacturer's ICA's mandatory for all maintenance performed under Part 43 (unless the FAA approves an alternative), and 14 CFR 43.1(a) which makes Part 43 applicable to maintenance of all aircraft with a U.S. airworthiness certificate other than those with an Experimental or Special airworthiness certificate -- and I'm pretty sure the OP's plane has a Standard Airworthiness Certificate.

 

[RotorAndWing]

It's not anything in the ICA's which make them mandatory, since they are written by the manufacturer, not the FA. It's 14 CFR 43.13(a) which makes the manufacturer's ICA's mandatory for all maintenance performed under Part 43 (unless the FAA approves an alternative), and 14 CFR 43.1(a) which makes Part 43 applicable to maintenance of all aircraft with a U.S. airworthiness certificate other than those with an Experimental or Special airworthiness certificate -- and I'm pretty sure the OP's plane has a Standard Airworthiness Certificate.

FAA Order 8110.54A

 

[poadeleted20]

FAA Order 8110.54A

Not exactly relevant to this discussion, since the issue here is only whether the ICA must be followed by a maintainer, not how to write one and get it approved by the FAA.

2. Audience. [FONT=Times New Roman,Times New Roman][FONT=Times New Roman,Times New Roman]This order is for personnel in the Aircraft Certification Service (AIR) and the Flight Standards Service’s (AFS) aircraft evaluation groups and flight standards district offices (FSDO) that review then accept ICA as required by the regulations and related policy.
[/FONT][/FONT]

It's 43.13(a), not FAA Order 8110.54A, which makes use of the ICA mandatory by persons performing maintenance under Part 43 (like Tom and the OP's mechanic).

 

[RotorAndWing]

Not exactly relevant to this discussion, since the issue here is only whether the ICA must be followed by a maintainer, not how to write one and get it approved by the FAA.
It's 43.13(a), not FAA Order 8110.54A, which makes use of the ICA mandatory by persons performing maintenance under Part 43 (like Tom and the OP's mechanic).

How about try reading the contents, some very enlightening information in there.

 

[poadeleted20]

How about try reading the contents, some very enlightening information in there.

Not going to hunt through 69 pages just for enlightenment. If there's a specific point you want to make, just point it out.

 

[RotorAndWing]

Not going to hunt through 69 pages just for enlightenment. If there's a specific point you want to make, just point it out.

I'm not going to spoon feed you stuff that's well above your understanding to begin with.

When I want to educate myself on a subject, I do the research and reading. And when I have a question on Airworthiness questions I certainly don't seek out a CFI (with no maintenance background) for an answer.

 

[Henning]

Go read AC 20-37E.

Yes, I have, would you care to point out the clarifying verbiage that delineates when the paint on a propellor must be renewed that would allow one to not repaint/touch up paint the prop every time you smooth a nick or burr, or even finding it eroded from rain or sand on pre/post flight? I didn't see it there or in the referenced 43-4.

According to the ICAs that Ron referenced, you pretty much need to paint it every time you touch it if dressing the blade is a repair.

Do you concur with Ron's position that the McCaully prop cannot be returned to service legally in accordance with the ICA without also repairing the finish?

If not, what evidence do you bring to your argument?

 

[RotorAndWing]

Yes, I have, would you care to point out the clarifying verbiage that delineates when the paint on a propellor must be renewed that would allow one to not repaint/touch up paint the prop every time you smooth a nick or burr, or even finding it eroded from rain or sand on pre/post flight? I didn't see it there or in the referenced 43-4.

According to the ICAs that Ron referenced, you pretty much need to paint it every time you touch it.

Do you concur with Ron's position that the McCaully prop cannot be returned to service legally in accordance with the ICA without also repairing the finish?

If not, what evidence do you bring to your argument?

AC 35-4-1

 

[poadeleted20]

AC 35-4-1

...which begins "This AC addresses preparing the instructions for continued airworthiness (ICA) for propellers." Again, irrelevant to the discussion about the requirement to use an ICA which is already approved.

 

[Henning]

AC 35-4-1

Once again you have given a reference in which verbiage that counters Ron's position is not in evidence. Nor have you stated your position of agreement or disagreement.

 

[RotorAndWing]

...which begins "This AC addresses preparing the instructions for continued airworthiness (ICA) for propellers." Again, irrelevant to the discussion about the requirement to use an ICA which is already approved.

I've given 2 documents that contain a lot of information on how the manufacturers arrive at an ICA and how they are implemented.

You clearly don't get it, and I'm not going to waste my time with you. This whole discussion (as most airworthiness discussions) is way over your head.

 

[Checkout_my_Six]

...which begins "This AC addresses preparing the instructions for continued airworthiness (ICA) for propellers." Again, irrelevant to the discussion about the requirement to use an ICA which is already approved.

It's in there....keep reading.

do a word search for 14 CFR 91 operations.....

 

[RotorAndWing]

Once again you have given a reference in which verbiage that counters Ron's position is not in evidence.

Been watching old episodes of "Law and Order"??

Nor have you stated your position of agreement or disagreement.

I refuse to argue with idiots. I presented factual documents and let the reader draw his/her own conclusion.

See post #116

 

[poadeleted20]

It's in there....keep reading.

do a word search for 14 CFR 91 operations.....

You mean this?

3. RELATED REGULATIONS, ORDERS, AND ADVISORY MATERIAL.​

a. Related Regulations.​

(1) Part 21 – Certification Procedures for Products and Parts.​

(2) Part 35 – Airworthiness Standards: Propellers.​

(3) Part 43 – Maintenance, Preventive Maintenance, Rebuilding, and Alteration.​

(4) Part 91 – General Operating and Flight Rules.

That's the only mention of "Part 91" in AC 35.4-1, and there's no mention of 14 CFR 91 or 14 CFR Part 91. And I've read all 11 pages of that AC and find nothing relevant to the question of whether or not a mechanic working on the OP's prop is required to follow the ICA from McCauley.

 

[poadeleted20]

I refuse to argue with idiots. I presented factual documents and let the reader draw his/her own conclusion.

I did -- and I have concluded that AC 35.4-1 had nothing to do with the OP's question. If you think otherwise, it would be nice if you pointed out what it says which you think does apply to the OP's question.

 

[Tarheelpilot]

If you get right down to the nut cutting no aircraft ever signed off by any IA is technically airworthy. The FAA defines "airworthy" as the aircraft conforms to its type design and is in a condition for safe operation.

The only aircraft I have ever seen that fully complied with its TCDS was an aircraft that was new and had zero hours on it. How can an IA be assured that the structures and all appliances on an aircraft are fully in compliance with the type certification standards. Every hour on an airframe or component diminishes its strength and airworthiness. At some point we have standards for removing items from service for repair, overhaul or replacement but once it has been used that 100% compliance to the TCDS is forever gone and by a strict interpretation not airworthy.