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Thread: Owner Manufactured Part..... ??

  1. #1
    richdolby's Avatar
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    Feb 2017
    Bristol, UK
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    Default Owner Manufactured Part..... ??


    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??

    Your advice greatly appreciated!!

    Rich D.

    DSC_0027.jpg fullsizeoutput_d7b.jpg
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  2. #2

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    Default Re: Owner Manufactured Part..... ??

    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.

  3. #3

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    Default Re: Owner Manufactured Part..... ??

    By the way, how much would you charge to make a pair for me?

  4. #4
    JPerkins's Avatar
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    Aug 2014
    Cordova, Alaska
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    Default Re: Owner Manufactured Part..... ??

    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).

    Sent from my SM-G930V using Tapatalk
    Jason Perkins

  5. #5
    richdolby's Avatar
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    Default Re: Owner Manufactured Part..... ??

    Quote Originally Posted by Tp109 View Post
    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:

    Carbon-fibre-22-twill-in-hand-close-up.jpg carbon-fibre-22-twill-3k-210g-blue-in-hand-close-up.jpg Carbon-Kevlar-Plain-Weave-188g-in-hand-close-up.jpg carbon-fibre-22-twill-210g-green-in-hand.jpg carbon-fibre-22-twill-3k-210g-red-in-hand-close-up.jpg spread-tow-carbon-fibre-22-twill-15mm-in-hand.jpg

    The final piece will have a hi-gloss finish - so can be left 'as-is', or finished by the aircraft owner to suit personal preference.

    I will get back to you once I've finalised the design, and costed the materials, etc...
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  6. #6
    Steve Pierce's Avatar
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    Default Re: Owner Manufactured Part..... ??

    Unfortunatley we lost Bill a few years ago but he was one of the good guys.


    "I" versus "We"

    by Bill O'Brien

    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

    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)

  7. #7
    Steve Pierce's Avatar
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    Default Re: Owner Manufactured Part..... ??

    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,

    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

    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

    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

    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

  8. #8
    richdolby's Avatar
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    Default Re: Owner Manufactured Part..... ??


    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.

    Many Thanks,

    Rich D.

  9. #9

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    Aug 2012
    Kewanee, IL
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    Default Re: Owner Manufactured Part..... ??

    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....

  10. #10
    Vagabondblues's Avatar
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    Default Re: Owner Manufactured Part..... ??

    Quote Originally Posted by blueshortwing View Post
    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.


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