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OK; I'm in need of a little education regarding how the FAA operates with regard to what I have seen described as an 'Owner Manufactured Part'?
I am fortunate to operate a very nice 1951 PA-20 here in the UK. She is here on an 'N' registration (N1502A), and so operated just as though she were still resident in the United States.
She is fitted with what I believe to be the originally installed wheel pants, see photo's...
I am taking moulds, and plan to manufacture with Carbon-Fibre what will be in effect exact copies of the originals. The reason for doing this is because replacements are not available, and although the originals are OK, they're probably not up to having me stand on them when I'm filling the wing tanks with AvGas.
The Carbon-Fibre copies will be easily as strong, and certainly lighter - so the Big Question is... how would this work with the FAA?? Does an 'Owner Manufactured Part' mean just that, i.e. that I can fit the Carbon-Fibre wheel pants that I've manufactured myself, and that closely follow the original design; to my own aircraft??
I'm curious what the UK faa rules are? I am not sure what the FAA rules are on fenders or pants whatever they are called, but I know people make new cowlings and nose bowls themselves.
It can be considered owner produced if you bring whatever info is needed to make said part to a facility that specializes in the processes to make said part.
In other words, you could have a fiber glass shop make the wheel pants with your instructions (i.e. make me a set that look just like these).
I would recommend having an A&P look over your info before starting the project to make sure things where built to FAA standards (because they will need to be to legally bolt them onto your bird).
By the way, how much would you charge to make a pair for me?
I'll be happy to manufacture a pair for you - I am settling down to make the moulds now, and will be taking a look at various options for carbon-fibre/kevlar laminates with a core-material reinforcement, to ensure that they're plenty strong enough.
There are several options regarding final finish/appearance, as these days there are a good selection of carbon-fibre weaves available, here are some of the options:
Along with the pilot shortage and the mechanic shortage,
there is also a parts shortage that plagues the general
aviation industry. Because supply and demand are out of
balance the cost of new and used parts seem to increase
every day. Let's examine the reasons why this is so.
First, we have an old fleet. The average general aviation
(GA) single engine airplane is approximately 32 years old.
The average age of GA multi-engine reciprocating aircraft is
close to 27 years old. The average age for the turbine
powered multi-engine propeller driven aircraft average out
around 19 years of age. So because of long term wear and
tear the demand for replacement parts and large
sub-assemblies is much greater today than it was even 10
years ago.
The second reason is our general aviation fleet has been well
maintained over the years. So well maintained in fact, the
average GA aircraft with a mid-time engine and decent
avionics has appreciated to two or three times its original
purchase price and is still climbing. Yet even in that land of
many zeros the older aircraft are still substantially lower in
price than the cost of a brand new aircraft with similar
performance numbers and equipment. So the value of older
aircraft in good shape are proven investments that over time
have beaten the DOW JONES average. So we have an
economic imperative on the part of the owners to keep
maintaining older aircraft in flying condition which
increases the demand for replacement parts.
The third reason is the increasing production costs to make a
part. Today aircraft manufacturers are not making makes and
models of aircraft in the same quantity they made them back
in the Seventies. So the production runs for parts are not as
frequent and not as many parts are produced. In addition, it
is not cost effective for a manufacturer to make a lot of parts
even if the unit price for each part is out of this world
because taxes on maintaining a large inventory of parts
would eat all of the profits. This low parts production keeps
the supply of replacement parts low.
The fourth reason is that some manufacturers would prefer
that their older makes and model aircraft-made a million
years ago-would quietly disappear from the aircraft registry.
This retroactive birth control on the part of the
manufacturers may seem not to make any sense until you
look at aircraft market dynamics of creating demand and
reducing costs. First, each older aircraft that is no longer in
service creates a demand for a new, more expensive aircraft
to take its place. Second, despite some tort claim relief
granted to GA manufacturers in the early Nineties, the fewer
older aircraft there are in service, the manufacturers of those
aircraft enjoy reduced overall liability claims and ever
decreasing continuing airworthiness responsibilities.
So how are we going to maintain these older aircraft with an
ever dwindling parts supply when Part 21, section 21.303
Replacement and modification of parts, requires us to use
the Parts Manufactured Approval (PMA) parts on a type
certificated product? Well, the same rule grants four
exemptions to the PMA requirement.
1. You can use parts produced under a type or production
certificate such as a Piper, Cessna, or Mooney produced
part;
2. A owner or operator produced part to maintain or alter
their own product;
3. Parts produced under a Technical Standard Order (TSO)
such as radios, life vests and rafts, and GPS; or,
4. A standard aviation part such as fasteners, washers, or
safety wire.
Before I segue into the subject of "owner produced parts" as
called out in section 21.303, which is the purpose of this
article. I would like to create a small uproar with this
statement: "FAA Airframe and Powerplant rated mechanics
can maintain, repair, and modify parts, but they cannot make
a brand new part and call it a repair." Before you accuse me
of losing dendrites by the minute, check out section 65.81
General privileges and limitations. The section talks about
maintenance, preventive maintenance, and alterations, but
not the manufacturing of parts. Nor is it an implied privilege
in Part 65, because Part 21 section 21.303 says "no person"
may make a replacement part for a type certificated (TC)
product unless that person has a PMA, etc.
While I write this I can remember 25 pounds ago and when I
had hair, I worked in the real world and I specialized in
making engine baffles for Lycoming engines. Before
someone accuses me of bureaucratic ventriloquism which is
roughly translated as "talking out of both sides of my
mouth." My weak defense is, I made the parts because I
thought I could." It never dawned on me that I could not
legally make a part. Some of you may be astounded that I
make this confession freely. It's no big thing because I know
the statue of limitations has run out years ago and a jury of
my peers would never look me in the eye and convict me.
So here is our problem that we must solve. Since mechanics
cannot legally make parts for aircraft and aircraft need
replacement parts, how are we going to keep the fleet
flying? If we cannot find PMA, TSO, standard, or
production holder replacement parts, we are left to make the
part under the owner-produced option under section
21.303(b)(2). However, we must remember that the part is
for the owner/operator's aircraft only and is not
manufactured for sale to other TC aircraft.
To get through confusing regulatory policy with our pride
intact, let's try the question and answer routine. (Note: This
policy is taken from FAA 's AGC-200 policy memorandum
to AFS-300 on the definition of "Owner-Produced Parts"
dated August 5, 1993)
.
Question 1: Does the owner have to manufacture the part
him or herself in order to meet the intent of the rule?
Answer 1: No, the owner does not have to make the part him
or herself. However to be considered a producer of the part
he/she must have participated in controlling the design,
manufacturer, or quality of the part such as:
1. provide the manufacturer with the design or performance
data from which to make the part, or
2. provide the manufacturer with the materials to make the
part, or
3. provide the manufacturer with fabrication processes or
assembly methods to make the part, or
4. provide the quality control procedures to make the part,
or
5. personally supervised the manufacturer of the part.
Question 2: Can the owner contract out for the manufacture
of the part and still have a part that is considered
"owner-produced?"
Answer 2: Yes, as long as the owner participated in one of
the five functions listed in Answer 1.
Question 3: Can the owner contract out the manufacture of
the part to a non-certificated person and still have a part that
is considered "owner-produced?"
Answer 3: Yes, as long as the owner participated in one of
the five functions listed in Answer 1.
Question 4: If a mechanic manufactured parts for an owner,
is he/she considered in violation of section 21.303(b)(2)?
Answer 4: The answer would be no, if it was found that the
owner participated in controlling the design, manufacture, or
quality of the part. The mechanic would be considered the
producer and would not be in violation of section 21.303(a).
On the other hand, if the owner did not play a part in
controlling the design, manufacture, or quality of the part,
the mechanic runs a good chance of being in violation of
section 21.303 (b)(2).
Question 5: What kind of advice can you give on how a
mechanic can avoid even the appearance of violating section
21.303(b)(2)?
Answer 5: First, a mechanic should never make a logbook or
maintenance entry saying that he/she made a part under his
certificate number. This foopah will send up a flare and get
you undue attention from your local FAA inspector, which
you could do without. However, the mechanic can say on the
work order that he helped manufacture an owner-produced
part under section 21.303 (b)(2).
Second, the owner or operator should be encouraged to
make a log book entry that is similar to section 43.9
maintenance entry that states: The part is identified as an
owner produced part under section 21.303 (b)(2). The part
was manufactured in accordance with approved data. The
owner/operator's participation in the manufacturer of the
part is identified, such as quality control. The owner must
declare that the part is airworthy and sign and date the entry.
Question 6: Is there anything else a mechanic must do?
Answer 6: The mechanic must ensure that the
owner-produced part meets form, fit, and function, and,
within reasonable limits, ensure that the part does meet its
approved type design (e.g. like looking at the approved data
used to make the part). Then the mechanic installs the part
on the aircraft, makes an operational check if applicable,
and signs off the required section 43.9 maintenance entry.
Question 7: What is the owner responsible for and what is
the mechanic responsible for concerning owner-produced
parts?
Answer 7: The owner is responsible for the part meeting
type design and being in a condition for safe operation. The
mechanic is responsible for the installation of the
owner-produced part being correct and airworthy and for a
maintenance record of the installation of the part made.
Question 8: How does the owner or operator get the
approved data to make a part if the manufacturer and other
sources are no longer in business?
Answer 8: For aircraft that the manufacturer is no longer
supporting the continuing airworthiness of, the owner or
operator can petition the FAA Aircraft Certification
Directorate under the Freedom of Information Act for the
data on how the part was made. Or the owner or operator
can reverse engineer the part and have the data approved
under a FAA field approval or, if it is a really complicated
part, have the data approved by a FAA engineer or FAA
Designated Engineering Representative.
Question 9: What happens to the owner-produced part on
the aircraft if the original owner sells the aircraft?
Answer 9: Unless the part is no longer airworthy, the
original owner-produced part stays on the aircraft.
I hope that I spread some light on the murky subject of
owner-produced parts, so the next time instead of saying to
the owner of an broke aircraft: "Sure, 'I' can make that part,"
you will now say "Sure, 'WE' can make that part."
Bill O'Brien is an Airworthiness Aviation Safety Inspector
in FAA's Flight Standards Service. This article also
appeared in the Aircraft Maintenance Technology
magazine
It is going to take me a while to digest this, but what a gold-mine of information, and so clearly explained - this has helped clarify the situation very well.
The one problem I see with your theory is that to use "owner produced" you must make the part EXACTLY like the original. If original are fiberglass then the "new" ones must be fiberglass. Technically you must use the same spec fiberglass and same spec epoxy, etc. Having the original Piper drawings are one way. Analyzing the old part is another. A good example of "owner produced" is replacing a wooden wing spar. If you have the original part (could be broken), you can take a piece of aircraft grade spruce and shape it to be an exact duplicate of the original. If you attempt to substitute the material it is made from, that constitutes an alteration and does not fall into the "owner produced" arena. Or......you could say.....what, those old things....
The one problem I see with your theory is that to use "owner produced" you must make the part EXACTLY like the original. If original are fiberglass then the "new" ones must be fiberglass.
I think that both of the Advisory Circulars (fabrication of parts and substitution of parts on old aircraft) give you some wiggle room in the "EXACT" form fit and function standard. First, the wheel fender is probably not a "primary" structural component. Most likely "Secondary" which under the AC's allow the substitution of materials as a minor alteration. Carbon fiber is off the charts in both tensile strength and bearing strength in comparison to the 3003H14 aluminum that it would be replacing, but I would not replace all of it. Kind of like they do in the aircraft exhaust overhaul business, keep one original bracket, and replace all the tubing. The description of the work performed entered in the log by a certificated person would be "replaced wheel fender skins with owner supplied fabricated skin". Mechanic did the parts replacement, owner fabricated, contracted, had them made or whatever, received them in under a quality process, parts (wheel fender skins) consumed in repair.
The only caution I can think of is the high galvanic action between carbon fiber and steel and aluminum. You would have to paint all contacting parts with epoxy paint and seal contacting surfaces to prevent water from entering. All attaching hardware would have to be plated and coated with a dielectric.
Thanks: 
Likes: 
Owner Manufactured Part..... ??
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Originally Posted by Tp109
