AMT question: Approved Data

Hello.

I am studying for my O&Ps and I have a question about "approved data" and
"acceptable data."

I understand that the manufacturer's maintenance manual is only considered
"acceptable data," and is therefore not approved for use in making major
repairs or major alterations.

So let's suppose I want to overhaul some big nasty Lycoming with an integral
supercharger and a planetary-type prop reduction gear. Per CFR Part 43
Appendix A, this is a powerplant major repair. What is my approved data? Is
the Lycoming overhaul manual a source of approved data? If so, what is the
difference between this overhaul manual and a "maintenance manual" as
defined in CFR Part 43 Appendix A?

Second question:

Suppose I crumpled some skin on the wing of my Cessna 172. Assuming that it
is economically feasible to undertake a major repair to correct this damage,
where would I find my approved data? A Cessna 172 Structural Repair Manual
seems like the obvious choice, if there is such a publication. Again, would
this not be considered a "maintenance manual?"

Thanks
-Mark

"Mark" wrote in message
...
Hello.

I am studying for my O&Ps and I have a question about "approved data" and
"acceptable data."

I understand that the manufacturer's maintenance manual is only considered
"acceptable data," and is therefore not approved for use in making major
repairs or major alterations.

So let's suppose I want to overhaul some big nasty Lycoming with an
integral supercharger and a planetary-type prop reduction gear. Per CFR
Part 43 Appendix A, this is a powerplant major repair. What is my approved
data? Is the Lycoming overhaul manual a source of approved data? If so,
what is the difference between this overhaul manual and a "maintenance
manual" as defined in CFR Part 43 Appendix A?

Second question:

Suppose I crumpled some skin on the wing of my Cessna 172. Assuming that
it is economically feasible to undertake a major repair to correct this
damage, where would I find my approved data? A Cessna 172 Structural
Repair Manual seems like the obvious choice, if there is such a
publication. Again, would this not be considered a "maintenance manual?"

Thanks
-Mark



Mark,

It can be very confusing between acceptable data and approved data. Some of
the data in the manufacturers maintenance manual is likely "approved" data,
but most is "acceptable." AC43-13 is also considered "acceptable" data.

On a major repair "acceptable" data is acceptable! It becomes "approved"
when they accept the 337. Approved data is required for major alterations.
For this purpose the data provided with the STC or on the TCDS is approved
data. The difference becomes important on a "field modification." Then you
write up the 337 explaining what you are going to do and how you will do it
referring to what approved data you have and acceptable data where you do
not have approved data. Make sure you include all sixteen points of the
ICA even if you only put down N/A for most of them. Then you send it off to
the FSDO before you do any of the work. They will put their stamp and
signature in Block 3 of the 337 and when they do all of your writeup becomes
approved. Then you perform the work exactly like you said you were going
to, and have the IA do the "return to service."

A major overhaul is "minor" maintenance and does not require a 337 form.
Welding up a crack in a seat frame is a "major" repair and does require a
337. :-) In my FSDO replaceing any factory part is minor maintenance and
just requires a logbook entry unless the part is something like a skin panel
that requires rivits to attach. Then it becomes a "major" repair because of
the rivits and requires a 337.

Putting in any avionics that is not listed on the TCDS, which these days is
virtually all avionics, requires a 337.

If ever you are not sure about something, call you PMI at the local FSDO and
talk it over. They will be glad to tell you what they will require from
you. If you give them what they need, all should go smoothly. I has worked
well for me over the years.

Highflyer
Highflight Aviation Services
Pinckneyville Airport ( PJY )

On Fri, 24 Mar 2006 14:59:51 -0800, "Mark"
wrote:


Second question:

Suppose I crumpled some skin on the wing of my Cessna 172. Assuming that it
is economically feasible to undertake a major repair to correct this damage,
where would I find my approved data? A Cessna 172 Structural Repair Manual
seems like the obvious choice, if there is such a publication. Again, would
this not be considered a "maintenance manual?"

Thanks
-Mark


Cessna 100 series service manual.
this is for the 150, 172, 175, 180, 182 and 185 if yours is the same
vintage as mine ( 1962 and prior)

this has details of the repairs you mention.
they are available from Univair

Stealth Pilot

"Stealth Pilot" wrote:

Cessna 100 series service manual.
this is for the 150, 172, 175, 180, 182 and 185 if yours is the same
vintage as mine ( 1962 and prior)

this has details of the repairs you mention.
they are available from Univair

Thanks for the information. However, my question is hypothetical.
I'm studying for the A&P exams.

-Mark

"Mark" wrote in message
So let's suppose I want to overhaul some big nasty Lycoming with an
integral
supercharger and a planetary-type prop reduction gear. Per CFR Part 43
Appendix A, this is a powerplant major repair.

Wouldn't you need an IA to go along with the A&P to perform this operation?

D.

"Capt.Doug" wrote in message
...
"Mark" wrote in message
So let's suppose I want to overhaul some big nasty Lycoming with an
integral
supercharger and a planetary-type prop reduction gear. Per CFR Part 43
Appendix A, this is a powerplant major repair.

Wouldn't you need an IA to go along with the A&P to perform this
operation?


No, you would need the IA for return to service. The A&P can DO the
overhaul; the IA is needed for return to service.

Jim

RST Engineering wrote:
"Capt.Doug" wrote in message
...

"Mark" wrote in message
So let's suppose I want to overhaul some big nasty Lycoming with an

integral

supercharger and a planetary-type prop reduction gear. Per CFR Part 43
Appendix A, this is a powerplant major repair.

Wouldn't you need an IA to go along with the A&P to perform this
operation?



No, you would need the IA for return to service. The A&P can DO the
overhaul; the IA is needed for return to service.

Jim


Ackshully, you would need an appropriately rated pilot for return to
service. You'd need an IA to approve the engine for return to service.
And yes, the pilot is supposed to make an engine log entry.

"Dale Scroggins" wrote:

Ackshully, you would need an appropriately rated pilot for return to
service. You'd need an IA to approve the engine for return to service.
And yes, the pilot is supposed to make an engine log entry.

If I did the overhaul, then he also gets a beer. Or two. :-)

Ackshully, you would need an appropriately rated pilot for return to
service. You'd need an IA to approve the engine for return to service. And
yes, the pilot is supposed to make an engine log entry.

I agree with you that the IA approves the engine for return to service, and
the pilot actually returns it to service. But what's your reference for
stating that the pilot is supposed to make a logbook entry? I'm not aware of
any such requirement in Part 43.

Putting in any avionics that is not listed on the TCDS, which these days is
virtually all avionics, requires a 337.

This is certainly true in practice, but adding avionics doesn't seem to me to
fit any of the definitions of major alterations given in Part 43 Appendix A.
I once asked an FAA avionics inspector about this, and he just said something
about it being critical to safety and thus it makes sense to require a 337.
Does anyone know of a case in which someone has tried to challenge the FAA's
interpretation of this?