Prop Clean Up

Rotor&Wing said:
This is from AC 20-37e:

205. LIMITATIONS. Operational and service personnel should be familiar with the following limitations during any inspection.

e. Blade Polishing. The FAA receives frequent inquiries from airplane owners and maintenance personnel asking whether it is acceptable to polish propeller blades. It is almost always not acceptable. Corrosion protection such as paint and anodize should not be removed from the surface of a propeller blade. Propeller blades must be maintained to the type design. If the original design had corrosion protection and the instructions for continued airworthiness call for corrosion protection, then the corrosion protection should be maintained to those instructions.

206. PROCEDURES FOR MAINTENANCE.
b. Operators Cannot Do the Following:

(8) Do not polish blades unless specifically permitted by the manufacturer’s instructions.
http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/895eff1883ee06768625707b00727fd6/$FILE/AC%2020-37e.pdf
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"Should not" is not a requirement. nor is any AC

plus the ICAs do not require the Anodizing to remain in place during service.and give no limits for how much can be removed and still be airworthy.
Type design does not give the protection given to a prop, it gives the spec for metal alloy, shape, and size. during manufacturing.
 
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There is a point that should be made in this thread,,

none of the prop manufacturers like you to remove the corrosion protection, but. none give a limit as to how much can be missing and still be airworthy.

Hamilton Standard, does give instructions to polish their props
McCauley says you shouldn't but gives no required forbidden statement.
Dido, Sensenich. because if they say that X amount is missing the prop will then be unairworthy, and must be returned to a prop shop with capabilities to Anodize.

All props that do not have ICAs are maintained IAW the 43,13, which gives no guidance as to polishing. And that is the FAA guidance to maintaining propellers.
 
Tom-D said:
There is a point that should be made in this thread,,

none of the prop manufacturers like you to remove the corrosion protection, but. none give a limit as to how much can be missing and still be airworthy.

Hamilton Standard, does give instructions to polish their props
McCauley says you shouldn't but gives no required forbidden statement.
Dido, Sensenich. because if they say that X amount is missing the prop will then be unairworthy, and must be returned to a prop shop with capabilities to Anodize.

All props that do not have ICAs are maintained IAW the 43,13, which gives no guidance as to polishing. And that is the FAA guidance to maintaining propellers.
Click to expand...

Good summary, thanks.
 
Tom-D said:
There is a point that should be made in this thread,,

none of the prop manufacturers like you to remove the corrosion protection, but. none give a limit as to how much can be missing and still be airworthy.

Hamilton Standard, does give instructions to polish their props
McCauley says you shouldn't but gives no required forbidden statement.
Dido, Sensenich. because if they say that X amount is missing the prop will then be unairworthy, and must be returned to a prop shop with capabilities to Anodize.

All props that do not have ICAs are maintained IAW the 43,13, which gives no guidance as to polishing. And that is the FAA guidance to maintaining propellers.
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Your "summary" is contrary to the AC. Advisory Circulars are not mandatory but the guidance in them are FAA recommendations.

Bottom line is the A&P performing the job (polishing) has to make a logbook entry. And that log book entry has to reference some sort of data.
 
Rotor&Wing said:
Your "summary" is contrary to the AC. Advisory Circulars are not mandatory but the guidance in them are FAA recommendations.

Bottom line is the A&P performing the job (polishing) has to make a logbook entry. And that log book entry has to reference some sort of data.
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I certainly don't log every time I swipe a rag over the prop... so at what point does an owner cross the line from "preventative maintenance" (cleaning, lubing, etc)?

I don't think wiping down the prop with a non-acidic cleaner such as Simple Green for Aircraft requires a logbook entry.

In fact 14 CFR 43

(c) Preventive maintenance. Preventive maintenance is limited to the following work, provided it does not involve complex assembly operations:....

(10) Applying preservative or protective material to components where no disassembly of any primary structure or operating system is involved and where such coating is not prohibited or is not contrary to good practices.
 
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Rotor&Wing said:
Bottom line is the A&P performing the job (polishing) has to make a logbook entry. And that log book entry has to reference some sort of data.
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And the only authorized Data is the ICAs written by the prop manufacturer. Which have no restrictions as to how much Anodizing can be removed in service.

Do you have an owners manual for your prop?
 
dmccormack said:
No -- I've looked up on Sensenich site but no joy...
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They have contact info there, you should hive one.

The only time I have seen an A&P get their butt chewed was for blending a prop with out following the proper manual. (No it was not me) the FAA inspector want to see the authorized data they had used, and the mechanic could not produce it.

FAR 43.9
(a) Maintenance record entries. Except as provided in paragraphs (b) and (c) of this section, each person who maintains, performs preventive maintenance, rebuilds, or alters an aircraft, airframe, aircraft engine, propeller, appliance, or component part shall make an entry in the maintenance record of that equipment containing the following information:

(1) A description (or reference to data acceptable to the Administrator) of work performed.

I asked the FAA inspector why he did not violate the A&P, he said it would not with stand NTSB appeal due to the "or" in the rule. because all any A&P needs to do is describe the work preformed.
 
OBTW does any one know who owned this aircraft? note the bright props.
 

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That was the FAA's DC-3
 
Update:

I emailed Sensenich and received a quick reply.

Summarized, it's ok to clean the prop with a non-alkaline cleaner such as Simple Green for Aircraft and then polish with ordinary car wax.
 
dmccormack said:
Update:

I emailed Sensenich and received a quick reply.

Summarized, it's ok to clean the prop with a non-alkaline cleaner such as Simple Green for Aircraft and then polish with ordinary car wax.
Click to expand...

Tolya........
 
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