You know you own an airplane when...

We'd known for some time that our A&P/IA has been cleaning & repairing
our 172's battery box every year. Usually it's just amounted to pulling
the battery, rinsing the box to neutralize the acid and sanding /
painting any areas where corrosion has gotten the better of it. The
last few years, however, the aluminum has been getting thinner, the
holes and cracks larger.

This year the word came down. "I've nursed it along all these years,
but if I put another patch on it we'll need to redo the weight and
balance", my mechanic woefully admitted. "Okay", I sighed. "What's the
damage on a new battery box?" "I don't know yet, but I'll let you know."

That was a couple weeks ago. Just got the call. A new battery box for
a 1971 Cessna 172L retails for (drumroll....) $1500. I nearly passed
out. And that's surprising only because I've been doing this airplane
ownership thing for a while so it takes a lot to phase me. I had to
ask. "Okay, that's ridiculous. You know I normally don't care if you
make some money on parts, but what's your cost on this?" He freely
admitted "$700...and I think that's crazy too, so I've decided that's
what I'm going to charge you for it."

All my partner (increasingly the miser) could say was "I could have
built it myself and welded the seams, etc. Would have been 10X better
looking & stronger than anything Cessna would build...and it would have
cost me maybe $50. I mean, it's a BOX for crying out loud!" I agreed,
but quickly pointed out that when I last checked we don't have any
"EXPERIMENTAL" stickers on the airplane and the feds wouldn't take
kindly to our "playing Cessna".

I don't know why, exactly, but I found myself actually happy to pay the
$700. It could have been worse, right? I suppose it only shows how bad
I have the aviation bug, even after all these years.

There's a long-running thread on a BMW message board I read called "You
know you drive an E36 when...." It contains lots of inside jokes about
all the stuff that goes wrong with these cars and the crap only a
diehard BMW owner would tolerate. It's actually really funny (at least
to us owners) though I'm fully aware others might diagnose our desire to
own these vehicles in spite of these problems as some kind of psychosis.
Browse here for a laugh, even if you don't own a BMW...

http://forums.bimmerforums.com/forum...ad.php?t=56053

Anyway, in that same vein I think we should start a thread here about
"You know you own an airplane when..." in which we can each give a
one-liner about our experiences as airplane owners. It's been done
before, but it's always nice to refresh the list. I'll start. You know
you own an airplane when...

....you're actually glad to get the news that a battery box will cost you
ONLY $700.

-Doug

--
--------------------
Doug Vetter, ATP/CFI

http://www.dvatp.com
--------------------

"Doug Vetter" wrote in message
...

All my partner (increasingly the miser) could say was "I could have built it
myself and welded the seams, etc. Would have been 10X better looking &
stronger than anything Cessna would build...and it would have cost me maybe
$50. I mean, it's a BOX for crying out loud!" I agreed, but quickly pointed
out that when I last checked we don't have any "EXPERIMENTAL" stickers on the
airplane and the feds wouldn't take kindly to our "playing Cessna".

Actually, under one of the exceptions to Part 21, section 21.303 is seems
that you (as the owner or operator) could have produced the part yourself
WITHOUT slapping that "experimental" sticker on your plane. Here is a good
discussion of that:
http://150cessna.tripod.com/obrienonownermadeparts.html

Vaughn Simon wrote:
"Doug Vetter" wrote in message
...
All my partner (increasingly the miser) could say was "I could have built it
myself and welded the seams, etc. Would have been 10X better looking &
stronger than anything Cessna would build...and it would have cost me maybe
$50. I mean, it's a BOX for crying out loud!" I agreed, but quickly pointed
out that when I last checked we don't have any "EXPERIMENTAL" stickers on the
airplane and the feds wouldn't take kindly to our "playing Cessna".

Actually, under one of the exceptions to Part 21, section 21.303 is seems
that you (as the owner or operator) could have produced the part yourself
WITHOUT slapping that "experimental" sticker on your plane. Here is a good
discussion of that:
http://150cessna.tripod.com/obrienonownermadeparts.html

Well, my Cessna was type certificated under CAR 3, so I doubt part 21
applies (probably would to the "new" Cessnas).

A few years back I went over this when we were refurbishing the airbox.
My mechanic told me that we weren't allowed to fabricate parts IF
there was an approved part available (presumably from any
manufacturer...PMA or OE). I remember this because he said an airbox
cost $1100 so we should make every attempt to save it (and we did).

-Doug

--
--------------------
Doug Vetter, ATP/CFI

http://www.dvatp.com
--------------------

"Doug Vetter" wrote in message ...

: Well, my Cessna was type certificated under CAR 3, so I doubt part 21
: applies (probably would to the "new" Cessnas).
:
: A few years back I went over this when we were refurbishing the airbox.
: My mechanic told me that we weren't allowed to fabricate parts IF
: there was an approved part available (presumably from any
: manufacturer...PMA or OE). I remember this because he said an airbox
: cost $1100 so we should make every attempt to save it (and we did).
:
: -Doug
:


That is 100% not true...

("Vaughn Simon" wrote)
All my partner (increasingly the miser) could say was "I could have built
it myself and welded the seams, etc. Would have been 10X better looking
& stronger than anything Cessna would build...and it would have cost me
maybe $50. I mean, it's a BOX for crying out loud!" I agreed, but
quickly pointed out that when I last checked we don't have any
"EXPERIMENTAL" stickers on the airplane and the feds wouldn't take kindly
to our "playing Cessna".

Actually, under one of the exceptions to Part 21, section 21.303 is
seems that you (as the owner or operator) could have produced the part
yourself WITHOUT slapping that "experimental" sticker on your plane. Here
is a good discussion of that:
http://150cessna.tripod.com/obrienonownermadeparts.html


http://150cessna.tripod.com/obrienonownermadeparts.html

VERY GOOD info he
http://150cessna.tripod.com/parts.html

(From the link)
Let’s examine the rules governing the general privileges and limitations of
a maintenance technician (or certificated mechanic as stated in FAR §65.81),
and the rule governing a repair station’s privileges of certificates (FAR
§145.51).

Under both rules a technician or repair station may perform maintenance,
preventative maintenance, and alterations on an aircraft, or appliances for
which he is rated. Nowhere in either rule does it say that the maintenance
technician or repair station can produce new parts! However, the maintenance
regulations allow the manufacture of parts for repair (see number 11 in next
question.

A maintenance tech or repair station can make patch plates, reinforcement
splices, and incorporate them into the repair of a part. But again, a,
maintenance technician cannot make a brand new part for sale.

Here are some answers to those earlier questions.

Question: who can make a brand new part?

Answer: FAA Advisory Circular 21-29, Detecting And Reporting Suspected
Unapproved Parts, states that there are eleven ways that a new part can be
made. They a

1. Parts Manufacturer Approval (PMA)
2. Technical Standard Order (TSO)
3. Type Certificate (TC) or Supplemental Type Certificate (STC)
4. TC with an Approved Production Inspection System (APIS)
5. Production Certificate (PC)
6. Bilateral Agreement
7. Any method acceptable to the Administrator.
8. Standard Parts (nuts and bolts)
9. Owner Produced Parts
10. Parts produced per STC instructions as part of an STC modification.
11. Fabricated by a qualified person in the course of a repair for the
purpose of returning a TC product to service (which is not for sale as a
separate part) under part 43.

All this sounds like bureaucratic alphabet soup, but, of all the ways
listed, "Owner Produced Parts" is the one most misunderstood. FAR
§21.303(b)2 makes a provision for an aircraft owner or operator to produce
parts for maintaining or altering his or her own product. Under this
provision, the Owner Produced Part can only be installed in an aircraft
owned or operated by that person and the Owner Produced Part cannot be
produced for sale to others.

Question:
How is it that an aircraft owner can produce a part, but a skilled
maintenance technician can’t?

Answer:
The responsibility follows the money. Most rules are written so the
responsibility for an action is placed with the person who has the economic
authority to make it happen. (The Golden Rule)

Question:
How does this owner-produced rule work? Does the owner have to make the part
himself?

Answer:
The answers can be found in a FAA Memorandum dated August 5, 1993, in which
the assistant Chief Counsel for Regulation makes the following
interpretation:

A part does not have to be solely produced by the owner to be considered an
Owner Produced Part. The aircraft owner must participate in the manufacture
of the part in at least one of five
ways for it to be considered an Owner Produced Part.

1. The owner provides the manufacturer of the part with the design or
performance data.
2. The owner provides the manufacturer of the part with the materials.
3. The owner provides the manufacturer with fabrication processes or
assembly methods.
4. The owner provides the manufacturer of the part with quality control
procedures.
5. The owner personally supervises the manufacture of the new part.

As anyone can see, the discriminators for determining owner participation in
a new part’s manufacture are very specific in the interpretation. Attachment
(A) to the 1993 Memorandum clearly stipulates that the FAA would not
construe the ordering of a part as participating in controlling the design,
manufacture, or quality of a part. The key point is that the aircraft owner
must participate in the part’s manufacture.

Question:
If the part is owner produced, is it also a FAA approved part? Can I install
it in the owner’s aircraft?

Answer:
If the Owner Produced Part has all the characteristics of an approved part,
is only installed on the owner’s aircraft, and is not for sale, it would be
considered a FAA approved part.

There are eleven ways (as listed earlier) to produce an FAA approved part.
It doesn’t matter if a part is produced under the authority of a PMA, TC, or
owner produced, it must have all the characteristics of an approved part.
The four characteristics of an approved part a

1. The part must be properly designed. A properly designed part means that
the part’s design is FAA approved. Depending on the complexity of the part,
a FAA approved design will have the following elements:

Drawings, specifications to define the part’s configuration and design
features.
Information on dimensions, materials, and processes necessary to define the
structural strength of the product.
Airworthiness limitations and instructions for continued airworthiness.
Any other data necessary to allow by comparison, the determination of
airworthiness of later products of the same type.

2. The part must be produced to conform to the design. A properly produced
part means the part conforms to the FAA approved design. Usually a properly
produced part will have the following characteristics:

The part complies with all applicable structural requirements of its design.
The materials and products conform to the specifications in the design.
The part conforms to the drawings in the design.
The manufacturing processes, construction, and assembly of the part conform
to those specified in the design.

3. The part’s production should be properly documented. A properly
documented part provides evidence that the part was produced under an FAA
approval and memorializes the production of the part.

4. The part must be properly maintained. A properly maintained part means
that the part is maintained in accordance with the rules prescribed under
FAR Part 43.

It is relatively easy for a part to meet the requirements of the August 5,
1993, Memorandum and qualify as an Owner Produced Part.

The four characteristics of an approved part are like the four legs of a
table with all four legs "equally sharing" the burden of an approved part.
If one leg is missing, the table will fall over. In the same way, if any of
the four characteristics of an approved part is missing, then the part may
not be FAA approved.

A good example is the case of the Cherokee 140 with the collapsed nose gear,
mentioned and shown in the beginning of this article. The investigation
determined the following:

The original factory nose strut lower tube was pitted.
The aircraft owner had a strut tube locally manufactured.
A technician who knew of the part’s origin installed the strut tube.
The strut tube failed during the first operation, resulting in $7,000+ in
damages.

Question:
Was the strut-tube an Owner Produced Part?

Answer:
Yes, legally it was an Owner Produced Part. The aircraft owner did
participate in the manufacture of the part. The owner supplied the
manufacturer a design for the part. He did this by giving the manufacturer
the old lower strut tube and told him to duplicate it. (Reverse engineer)

Question:
Was this a FAA approved part?

Answer:
No, the part was not approved because the owner did not provide the
manufacturer with an approved design or its equivalent. The part was not
approved because it did not conform to the material specifications
prescribed in the approved design. The part failed during its first
operation and didn’t last long enough for maintenance to be a factor.

Question:
Did the part producer (aircraft owner) or the maintenance technician who
installed the strut-tube violate the FAR? Who should be held accountable?

Answer:
The answer is both! The maintenance technician violated the rule the moment
that he signed the maintenance records and approved the aircraft to return
to service with the knowledge the part he installed was unapproved, that is
he apparently understood that the part was produced by the owner. The
question he should have asked the owner was "how the part was produced so as
to meet the performance rules of part 43.13 of the Federal Aviation
Regulations." The aircraft owner violated the rule when he knowingly
operated the aircraft with an unapproved and undocumented part installed.

Question:
This incident with the Cherokee 140 was wasteful, tragic, and dangerous. If
the aircraft owner wanted to make an Owner Produced Part, what should he
have done?

Answer:
The owner should have used the original manufacture’s prints and
specifications (FAA approved design). It would have saved him time, money,
and maybe his life.

Reverse engineer to develop a design if you must, but do your research and
submit the resulting design to the FAA for approval. Depending on the
complexity of the part, reverse engineering may result in a new design. This
design is the aircraft owner’s, not the original manufacturer’s, and is not
automatically FAA approved. The finished part must still meet the
requirements of the performance rules of section 43.13. Always contact your
local FSDO for guidance.

Produce the new part to conform to the approved design. Nothing more,
nothing less. Stronger is not always better.

The aircraft owner (part’s producer) or the technician who installs the part
should document or memorialize the production of the part in the aircraft
records. It would be wise if the installing technician requires the part
producer (aircraft owner) to memorialize the parts production in the
aircraft records with a statement worded in a similar form as the one below,
on this page.

After the part producer memorializes its production. The installing
technician must make a maintenance record entry indicating that he or she
installed the part. After all, installing the Owner Produced Part is a
maintenance function.

Aircraft owners can perform preventative maintenance, but not maintenance.

Eliminating the Confusion:
A maintenance technician can repair a part, but sometimes the distinction
between repairing a part and producing a brand new part is hard to
determine. The circumstances surrounding the repair, the part’s complexity,
availability of manufacturer’s data, and industry practices all are
determining factors. For a lack of a better term I call making this
determination the "Test of Reasonableness."

Example Scenario:
An aircraft wing is damaged. The damaged parts include a wing rib, a 24-inch
stringer, and wing skin. The aircraft Structural Repair Manual provides
material specifications for the skin and stringer. A new wing rib is
purchased from the aircraft manufacturer and the technician fabricates a
stringer and wing skin using the damaged parts as a template. The technician
installs these parts and repairs the wing in accordance with the
manufacturer’s instructions.

Is this a repair or did the technician produce a new part? The stringer and
wing skin do have a part number in the parts catalog for that aircraft, so
let’s consider the following facts:

The material specifications were published and readily available.

The parts were simple and the fabrication processes for the parts involved
common tools, skills, and standard industry practices.

Templates for the reliable reproduction of the parts were available
(Design).

The parts were incorporated into a repair in accordance with the
manufacturer’s instructions.

In this case, the "Test of Reasonableness" would determine this to be
considered a repair, even though the technician did fabricate a stringer and
skin.

Reality Check:
Maintenance technicians must face a cold hard fact. Aircraft owners can make
parts, but they cannot install them. Installing Owner Produced Parts is a
maintenance function and only technicians can do that. That makes
technicians the "gatekeepers" for parts and guardians against the
introduction of substandard and unapproved parts into the fleet. Under this
rule the responsibility is the technician’s to determine airworthiness
before returning the product to service. There is no one else to shift the
burden of blame to. The technician’s name is on the blame line.

Owner Produced Parts can be summarized as follows:
Under the Federal aviation regulations, aircraft owners can produce a brand
new part for their aircraft; technicians and repair stations can’t.

For a part to be considered "owner produced," the owner must have
participated in its manufacture in at least one of the five ways prescribed
in the 1993, Memorandum.

An Owner Produced Part must have all four characteristics of an approved
part before it is considered a FAA approved part and eligible for
installation.

Sometimes the distinction between producing a new part and making a repair
is hard to determine. When in doubt call the local FSDO and ask for
guidance.

Maintenance technicians are the gatekeepers for parts entering service in
the fleet. Technicians bear the lion’s share of the responsibility. The
technician’s name is on the blame line.

The availability of parts is a constant problem with our aging general
aviation fleet. As time passes, Owner Produced Parts may be the only
alternative available for maintaining some of it. With the passage of time,
technicians are going to be increasingly forced to face the challenge of
determining the airworthiness of Owner Produced Parts.

There are five points summarized here. Remember the five and stay alive!

(Montblack here)
After much reading, my take is:
1. Look at another similar Cessna battery box
2. Measure it
3. Research the part
4. Supply the proper dimensions & material to the builder
5. Inspect their work
6. Once completed, hand it to your wrench
7. Ask him/her to install the Owner Produced Part
8. Note the "maintenance" in your logbook

$150 to get the part made - and installed?


Montblack

.... a 3" x 3" piece of 1/16" lexan with two stickers, a rivet through it,
and a finger hole costs $150 NOS or $245 from Piper.

(Aztec emergency exit/window latch cover. When I lost it, I thought it was
moulded. Wrong. It's flat. I could have bought the stickers for $30 each,
made the cover, and saved $90)
Jim

Jim Burns wrote:
... a 3" x 3" piece of 1/16" lexan with two stickers, a rivet through it,
and a finger hole costs $150 NOS or $245 from Piper.

You know you own a beechcraft when you consider buying a roll of steel
cable at the hardware store for $50. Figure you will cut it up in 20
foot chunks, sell them to your other beech friends and get rich.
After all, RAPID (Raytheons parts distributer) does that and gets
$700 for each chunk.

--
Frank Stutzman
Bonanza N494B "Hula Girl"
Hood River, OR (soon to be Boise, ID)

Ï "Doug Vetter" Ýãñáøå óôï ìÞíõìá
...

.................................................. .......................
Anyway, in that same vein I think we should start a thread here about "You
know you own an airplane when..." in which we can each give a one-liner
about our experiences as airplane owners. It's been done before, but it's
always nice to refresh the list. I'll start. You know you own an
airplane when...

...you're actually glad to get the news that a battery box will cost you
ONLY $700.
-Doug
--------------------
Doug Vetter, ATP/CFI

http://www.dvatp.com
--------------------



You KNOW this thread will end with uncotrollable
sobbing.......................
(Socata TB-20 owner)

Doug,
My bonanza has an after market stainless steel battery box and the paper
work to go with it. Maybe there's an alternative for cessna's too?
Dave
M35


Doug Vetter wrote:
We'd known for some time that our A&P/IA has been cleaning & repairing
our 172's battery box every year. Usually it's just amounted to pulling
the battery, rinsing the box to neutralize the acid and sanding /
painting any areas where corrosion has gotten the better of it. The
last few years, however, the aluminum has been getting thinner, the
holes and cracks larger.

This year the word came down. "I've nursed it along all these years,
but if I put another patch on it we'll need to redo the weight and
balance", my mechanic woefully admitted. "Okay", I sighed. "What's the
damage on a new battery box?" "I don't know yet, but I'll let you know."

That was a couple weeks ago. Just got the call. A new battery box for
a 1971 Cessna 172L retails for (drumroll....) $1500. I nearly passed
out. And that's surprising only because I've been doing this airplane
ownership thing for a while so it takes a lot to phase me. I had to
ask. "Okay, that's ridiculous. You know I normally don't care if you
make some money on parts, but what's your cost on this?" He freely
admitted "$700...and I think that's crazy too, so I've decided that's
what I'm going to charge you for it."

All my partner (increasingly the miser) could say was "I could have
built it myself and welded the seams, etc. Would have been 10X better
looking & stronger than anything Cessna would build...and it would have
cost me maybe $50. I mean, it's a BOX for crying out loud!" I agreed,
but quickly pointed out that when I last checked we don't have any
"EXPERIMENTAL" stickers on the airplane and the feds wouldn't take
kindly to our "playing Cessna".

I don't know why, exactly, but I found myself actually happy to pay the
$700. It could have been worse, right? I suppose it only shows how bad
I have the aviation bug, even after all these years.

There's a long-running thread on a BMW message board I read called "You
know you drive an E36 when...." It contains lots of inside jokes about
all the stuff that goes wrong with these cars and the crap only a
diehard BMW owner would tolerate. It's actually really funny (at least
to us owners) though I'm fully aware others might diagnose our desire to
own these vehicles in spite of these problems as some kind of psychosis.
Browse here for a laugh, even if you don't own a BMW...

http://forums.bimmerforums.com/forum...ad.php?t=56053

Anyway, in that same vein I think we should start a thread here about
"You know you own an airplane when..." in which we can each give a
one-liner about our experiences as airplane owners. It's been done
before, but it's always nice to refresh the list. I'll start. You know
you own an airplane when...

...you're actually glad to get the news that a battery box will cost you
ONLY $700.

-Doug

--
--------------------
Doug Vetter, ATP/CFI

http://www.dvatp.com
--------------------


--
David Harnitchek, PE

I used to own an older Bellanca Viking, a feature of which is the mahagony
plywood wing skin.

One annual we had to repair an ancient and badly repaired hole and patch in
the leading edge of the wing. A phone call to Bellanca (still in business
then) revealed that they could indeed sell me some leading edge plywood
(properly moulded into Viking airfoil leading edge shape), just tell them
how much we would need, then we could proceed with the appropriate scarfed
glue joint repair, and recover/repaint that section.

The cost?

$60

PER INCH!


We bought 15 inches..... $900. Item came in the mail, it only weighed
a few ounces.

Geez, I could have bought a battery box for that and had some left over!


Lee McGee
formerly Bellanca N7300V
Mount Aukum, CA