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DFH65

DFH65

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DFH65
Other than AC 43.13-1B, AC 20-37E, MacCauly SB 176E are there other documents that cover propeller repair specifically repairs to the tip. The documents and diagrams talk about dressing out nicks dings and dents in the propeller body but the only specific language I can find about tip repairs is this in AC 20-37E:

"(4) Blade Tip Damage. Refer to the propeller manufacturer’s maintenance documents
for instructions on how to repair this damage. However, if the manufacturer did not publish this
information, the following repairs can be made. For nicks, dents, pits, and cuts in the tip of
blades, repair in accordance with the procedures used for leading and trailing edge repair. Any
removal of the blade tip material that reduces the blade radius below the minimum specified for
the propeller manufacturer’s model designation and specific installation criteria is not permitted. "
 
DFH65 said:
are there other documents that cover propeller repair specifically repairs to the tip.
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Yes, but it depends on the prop where they are found. Usually they'll list field rework limits in either the specific owner/operator manual or in the maintenance manual for the prop.
 
Good point didn't look for the specific prop manual.

ETA: Still not much specific to the tip.
 
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I know that for the McCauley on my Mooney, NO reduction is radius is allowed.

So no tip work
 
C172/EM7653 square tip 172 prop.
 
I definitely not a prop expert.

However; I seem to recall McCauley props could be re-contoured from square tip to

elliptical. Maybe.

There is a “ Blade Drawing” that provides minimum serviceable dimensions at

different stations. Some the Minimum Chord measurements are taken from the

Trailing Edge forward. I think of this when I dress out the nicks!
 
How the damage occurred also plays into this. If it was a tip strike the engine likely needs a tear down and inspection.
 
Owners aren’t authorized to file props, and very few would know how. I doubt even my mechanic would mess with a tip. He’d send it to the prop shop.
 
Stewartb said:
I doubt even my mechanic would mess with a tip. He’d send it to the prop shop.
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I looked for data in the FARs similar to what we have in Canadian regulations. Up here the last 2% of the blade length has no limit on repair, as long as overall prop minimum length isn't reduced. I'd post the picture from the CARs but it's so small as to be almost unreadable.

As Jeff767 mentioned, the cause of the damage is an important consideration.
 
Dan Thomas said:
They don't have the deep detail on propeller blade repair.
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FYI: The McCauley owner manuals contain the field level maintence procedures to include field blade repair limits. Usually when the damage exceeds these limits its at the major repair level and needs to go to the a shop. MPC-26 covers most of the aluminum props:
https://mccauley.txtav.com/en/manuals
 
Bell206 said:
FYI: The McCauley owner manuals contain the field level maintence procedures to include field blade repair limits. Usually when the damage exceeds these limits its at the major repair level and needs to go to the a shop. MPC-26 covers most of the aluminum props:
https://mccauley.txtav.com/en/manuals
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Yes, I've seen that manual and have it here somewhere, but it doesn't give the detail that the 730720 manual does, which outlines how much damage and dressing is permissible in what areas of the blade span. The picture given us in the Canadian regulations is this one, and I've seen it in McCauley's OH/Repair manual:

g571s01-en.gif


The reg also has the other diagrams that the MPC26 manual has. The regulation itself says this, preceding the above diagram:

The field repair limits shown below can be applied, provided the tolerances of the appropriate blade specification are not exceeded. Repairs which exceed these limits may only be performed by an approved propeller overhaul organization.
 
Dan Thomas said:
The picture given us in the Canadian regulations
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The FARs dont address prop maintenance procedures. The only applicable rule to props is Part 65 which states a mechanic cant perform major repairs/alterations on a prop. So outside the owner manual limits we, in general, dont use the OH manual much as it is more tweaked toward the major side. Big gray area down here which most people punt to a shop even though there are a number of repairs an AP can perform.
 
Weight at the outer end of a lever is more critical than weight closer to the inner end. Length impacting balance is a consideration.
 
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