dynamic balance of a propeller

Tom-D

Tom-D

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Tom-D
A question for the group.

Read FAR 65.81
General privileges and limitations. (of an A&P)
(a) A certificated mechanic may perform or supervise the maintenance, preventive maintenance or alteration of an aircraft or appliance, or a part thereof, for which he is rated (but excluding major repairs to, and major alterations of, propellers, and any repair to, or alteration of, instruments), and may perform additional duties in accordance with §§ 65.85, 65.87, and 65.95. However, he may not supervise the maintenance, preventive maintenance, or alteration of, or approve and return to service, any aircraft or appliance, or part thereof, for which he is rated unless he has satisfactorily performed the work concerned at an earlier date. If he has not so performed that work at an earlier date, he may show his ability to do it by performing it to the satisfaction of the Administrator or under the direct supervision of a certificated and appropriately rated mechanic, or a certificated repairman, who has had previous experience in the specific operation concerned.

(b) A certificated mechanic may not exercise the privileges of his certificate and rating unless he understands the current instructions of the manufacturer, and the maintenance manuals, for the specific operation concerned.

Then read the requirements of a major repair or alteration of a propeller.

FAR 43-A
(3) Propeller major alterations. The following alterations of a propeller when not authorized in the propeller specifications issued by the FAA are propeller major alterations:

(i) Changes in blade design.

(ii) Changes in hub design.

(iii) Changes in the governor or control design.

(iv) Installation of a propeller governor or feathering system.

(v) Installation of propeller de-icing system.

(vi) Installation of parts not approved for the propeller.



Then tell me if dynamic balance of a propeller is legally done outside a certified propeller repair shop?

Do you not add weights to the propeller to alter the propeller's balance?

Is dynamic balancing procedures given in the ICAs for the propeller?
 
Are the weights always added to the propeller? As far as I know, the weights were added to the spinner on the 'kota. Really smoothed things out too.

Are the weights not approved?
 
Clark1961 said:
Are the weights not approved?
Click to expand...

You would have to look in the propeller parts list to see.

can a A&P do any thing in the field except minor maintenance?

Is balancing the propeller a minor or major repair.

read the definition of a major repair.

Major repair means a repair:

(1) That, if improperly done, might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness; or

(2) That is not done according to accepted practices or cannot be done by elementary operations.
 
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Tom-D said:
A question for the group.

Read FAR 65.81
General privileges and limitations. (of an A&P)
(a) A certificated mechanic may perform or supervise the maintenance, preventive maintenance or alteration of an aircraft or appliance, or a part thereof, for which he is rated (but excluding major repairs to, and major alterations of, propellers, and any repair to, or alteration of, instruments), and may perform additional duties in accordance with §§ 65.85, 65.87, and 65.95. However, he may not supervise the maintenance, preventive maintenance, or alteration of, or approve and return to service, any aircraft or appliance, or part thereof, for which he is rated unless he has satisfactorily performed the work concerned at an earlier date. If he has not so performed that work at an earlier date, he may show his ability to do it by performing it to the satisfaction of the Administrator or under the direct supervision of a certificated and appropriately rated mechanic, or a certificated repairman, who has had previous experience in the specific operation concerned.

(b) A certificated mechanic may not exercise the privileges of his certificate and rating unless he understands the current instructions of the manufacturer, and the maintenance manuals, for the specific operation concerned.

Then read the requirements of a major repair or alteration of a propeller.

FAR 43-A
(3) Propeller major alterations. The following alterations of a propeller when not authorized in the propeller specifications issued by the FAA are propeller major alterations:

(i) Changes in blade design.

(ii) Changes in hub design.

(iii) Changes in the governor or control design.

(iv) Installation of a propeller governor or feathering system.

(v) Installation of propeller de-icing system.

(vi) Installation of parts not approved for the propeller.



Then tell me if dynamic balance of a propeller is legally done outside a certified propeller repair shop?

Do you not add weights to the propeller to alter the propeller's balance?

Is dynamic balancing procedures given in the ICAs for the propeller?
Click to expand...

Yes legal, no weights on the prop, you bolt them to the spinner back plate.
 
Are we debating the angels on the head of a pin, again?
A&P have been balancing props for generations and every FSDO inspector in the country is aware of it..
Why is it even a question on here?
 
Tom-D said:
You would have to look in the propeller parts list to see.

can a A&P do any thing in the field except minor maintenance?

Is balancing the propeller a minor or major repair.

read the definition of a major repair.

Major repair means a repair:

(1) That, if improperly done, might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness; or

(2) That is not done according to accepted practices or cannot be done by elementary operations.
Click to expand...

Well if you want to be literal then (1) sez that cleaning and gapping plugs is a major repair.

(2) sez that the prop balance is not a major repair

Denny: Tom wants to argue today. No problem.
 
Clark1961 said:
Well if you want to be literal then (1) sez that cleaning and gapping plugs is a major repair.

(2) sez that the prop balance is not a major repair

Denny: Tom wants to argue today. No problem.
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Actually it was a question asked of me, and I didn't have a reference to back it up, and apparently no one here does either.

As far as wanting to argue, If that is what you think why make a post?

Henning, the spinner and backing plate are a part of the propeller. If you don't believe that try running with out one see what happens when the feds see it.

OBTW cleaning plugs is an accepted practice, and done as preventive maintenance.

Can you tell me the accepted practice is for balancing a prop? would doing it wrong effect the operation?

Just because every one has been doing it for years doesn't make it legal.
 
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Dr. O said:
Are we debating the angels on the head of a pin, again?
A&P have been balancing props for generations and every FSDO inspector in the country is aware of it..
Why is it even a question on here?
Click to expand...

Can you tell me what makes it legal?

If you were in process of doing it, and a airworthiness inspector walked into the shop, how would you convince them it was legal?
 
Tom-D said:
Actually it was a question asked of me, and I didn't have a reference to back it up, and apparently no one here does either.

As far as wanting to argue, If that is what you think why make a post?

Henning, the spinner and backing plate are a part of the propeller. If you don't believe that try running with out one see what happens when the feds see it.

OBTW cleaning plugs is an accepted practice, and done as preventive maintenance.

Can you tell me the accepted practice is for balancing a prop? would doing it wrong effect the operation?

Just because every one has been doing it for years doesn't make it legal.
Click to expand...

The spinner is not The Propellor, it is a part of the propellor assembly. There is no mention of the rest of the parts of the assembly, just the prop. Dude, BTW, you're an IA, don't you have a PMI at the FAA for asking this stuff?
 
Tom-D said:
Actually it was a question asked of me, and I didn't have a reference to back it up, and apparently no one here does either.

As far as wanting to argue, If that is what you think why make a post?

Henning, the spinner and backing plate are a part of the propeller. If you don't believe that try running with out one see what happens when the feds see it.

OBTW cleaning plugs is an accepted practice, and done as preventive maintenance.

Can you tell me the accepted practice is for balancing a prop? would doing it wrong effect the operation?

Just because every one has been doing it for years doesn't make it legal.
Click to expand...
See, I told'em you just wanted to argue. I'm just helping you out.
 
Hartzell has a 'Standard Practices Manual' that is stamped FAA approved and covers dynamic balancing. Not sure what props/hubs etc it applies too thou.


-VanDy
 
The AI that dynamically balanced my Cessna 185's prop, filed a 337 with the FAA.

End of story!
 
kgruber said:
The AI that dynamically balanced my Cessna 185's prop, filed a 337 with the FAA.

End of story!
Click to expand...

Cool, you have an Artificial Intelligence device that not only balances props but fills and files paperwork! Awesome:D;) IAs are A&Ps with an Inspection Autorization.
 
kgruber said:
The AI that dynamically balanced my Cessna 185's prop, filed a 337 with the FAA.

End of story!
Click to expand...

how can you make a major repair to a prop in the field when A&Ps are only allowed to do minor repairs.

I still do not understand that?
 
Tom-D said:
how can you make a major repair to a prop in the field when A&Ps are only allowed to do minor repairs.

I still do not understand that?
Click to expand...

Call your PMI, ask him and let us know. This isn't exactly new uncharted territory for them.
 
Tom-D said:
how can you make a major repair to a prop in the field when A&Ps are only allowed to do minor repairs.

I still do not understand that?
Click to expand...

Once the 337 gets signed by the FAA all is good!

And, they do it all the time.
 
Tom, I don't know. But he has a great relationship with the FAA. He manufactures at least 25 Cessna parts with PMA authority.
 
Tom-D said:
Reading that as a AC it says to follow the aircraft maintenance manual.

ever see those instructions in the cessna 100 service manual, or the 172 MM?
Click to expand...

I posted earlier that Hartzell has a manual.....


-VanDy
 
VanDy said:
I posted earlier that Hartzell has a manual.....-VanDy
Click to expand...

So, that gives us what?

a right to exceed the restrictions on the A&P certificate given in the FAR 65.81?
 
Tom-D said:
A

Read FAR 65.81
d (but excluding major repairs to, and major alterations of, propellers, and any repair to, or alteration of, instruments),

FAR 43-A
(3) Propeller major alterations. The following alterations of a propeller when not authorized in the propeller specifications issued by the FAA are propeller major alterations:


(vi) Installation of parts not approved for the propeller.



Then tell me if dynamic balance of a propeller is legally done outside a certified propeller repair shop?

Do you not add weights to the propeller to alter the propeller's balance?

Is dynamic balancing procedures given in the ICAs for the propeller?
Click to expand...

Tom-D said:
So, that gives us what?

a right to exceed the restrictions on the A&P certificate given in the FAR 65.81?
Click to expand...

IF the propeller specs list the manual and the manual lists how to do it, what parts to use, then it's not in violation of that at all.



-VanDy
 
VanDy said:
IF the propeller specs list the manual and the manual lists how to do it, what parts to use, then it's not in violation of that at all.-VanDy
Click to expand...

Big" if " isn't it.

which has president ? a FAR, or a Manufacturers manual?
 
Tom-D said:
Big" if " isn't it.

which has president ? a FAR, or a Manufacturers manual?
Click to expand...

President? You mean precedence? According to the FAA, the Manufacturers Manual is the governing document.
 
Tom-D said:
Big" if " isn't it.

which has president ? a FAR, or a Manufacturers manual?
Click to expand...

A VERY big if, but if being asked by a customer I would look at the prop specs and see if a manual with parts and instructions is available.

Without searching every Prop spec in existence I'd say its not a 100% always this or that.


-VanDy
 
Henning said:
According to the FAA, the Manufacturers Manual is the governing document.
Click to expand...

No it is not. the restriction on the A&P (FAR 65.81) says we can't work on props other than minor maintenance, which is the ICAs written by the manufacturer. (That is the owners manual for the prop) So until I'm shown where the FAA gives us the authority to do any thing except minor maintenance I believe the dynamic balancing by A&Ps in the field is not legal.

I believe the equipment, and technology did not exist when the rule (65.81) was written, thus the FAA simply ignores the issue, until some one makes an issue of it.
 
Tom-D said:
No it is not. the restriction on the A&P (FAR 65.81) says we can't work on props other than minor maintenance, which is the ICAs written by the manufacturer. (That is the owners manual for the prop) So until I'm shown where the FAA gives us the authority to do any thing except minor maintenance I believe the dynamic balancing by A&Ps in the field is not legal.

I believe the equipment, and technology did not exist when the rule (65.81) was written, thus the FAA simply ignores the issue, until some one makes an issue of it.
Click to expand...


Let us know what the PMI says next week, I'm still betting that the spinner isn't considered the propeller in this context, but an accessory to the prop.
 
Tom-D said:
No it is not. the restriction on the A&P (FAR 65.81) says we can't work on props other than minor maintenance, which is the ICAs written by the manufacturer. (That is the owners manual for the prop) So until I'm shown where the FAA gives us the authority to do any thing except minor maintenance I believe the dynamic balancing by A&Ps in the field is not legal.

I believe the equipment, and technology did not exist when the rule (65.81) was written, thus the FAA simply ignores the issue, until some one makes an issue of it.
Click to expand...

This kind of manual?
F2B02192-EF69-4796-AB80-7519E28AE45C-647-0000009C6F89AB4B.jpg


That has this section on dynamic balance?
7E76E8B0-30DB-4413-BA05-301BCDB3D5D9-647-0000009C757812F4.jpg






-VanDy
 
I wonder what McCauley does?
 
actually the spinner and bulkhead is really part of the air frame, the prop manuf. make the prop only, the air frame manuf. figures out how to fair that prop into the cowling. adding weights to a spinner bulkhead IAW the prop balancer manual only requires log book entry.
Only a prop manuf. or prop maint. shop can do any mods to a prop, including static balancing, A&P's do the dynamic balancing as it is also affected by things as stupid as which way the spinner is indexed to the spinner bulkhead (they usually have a heavier side) and if all the spinner screws match.
There are aircraft certified to fly with no spinner, it is an airframe manuf. created part.
 
Tom-D said:
So, I guess when I have a question I need medication.
Click to expand...

Not quite that Tom. It's when you argue with the responses instead of corresponding reasonably that you need medication. No big deal but that's how other folks see it.
 
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