Firewall

Yellowbird

Pre-takeoff checklist
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Apr 27, 2010
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Wooster, OH
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Yellowbird
Look what Santa brought yesterday: (Almost a year since we ordered it)
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Look what Santa brought yesterday: (Almost a year since we ordered it)


Holy moly there are a lot of holes in it :hairraise:. What are the odds those hole will match well? I sure hope it works out for you
 
Was it anywhere near the cessnaparts.com price of $1017?
 
Was it anywhere near the cessnaparts.com price of $1017?

That may be it, or close. I haven't seen the invoice yet, but my mechanic said that it was more than the $900 or so that they quoted us when we originally ordered it last January, and that was far more than the $200 or so he paid when he replaced a Cardinal firewall a couple of years ago.
 
The bite comes from the fact that when you need one of those old, out of stock parts, someone has to set up tooling to make one. Short production runs cost big bucks and they pass the cost on.

About ten years ago I ordered a cabin heat box for a 152. Price back then was $1200.

Edit: If the dies for a stamped part are no longer available you got a problem, Houston.
 
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There sure seems to be an awful disconect between the "GA" and "Corperate" worlds if you ask me. If you have an old jet and the part is out of stock, whether it be a seat track, stringer, skin, gusset or rib, they will almost always give out the material spec and dimensions and let you make your own replacement part. They won't give it out for free, but at least you can get'er done long before they can make it. If you need aluminum extrusion to machine a seat track, they'll help you find a blank.

Some service manuals go as far as giving you the material specs right there. I was looking into piper arrows and was shocked how much data they provide.
 
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I think after 3 months I would've cancelled the order and made one from scratch...
 
Well, since it took a year to get it, at least it's nice to see that the label says "no shelf life limit".

:)
 
I would not have waited 3 months...

That thing would have been fabricated the next day...:yes::idea:
The problem is the legalities associated with making parts for certified airplanes. You can do it IF you have the technical specifications. But Cessna isn't going to give or sell the drawings for that thing so you'd be guessing at which stainless it might be.

Long live homebuilts!

Dan
 
The problem is the legalities associated with making parts for certified airplanes. You can do it IF you have the technical specifications. But Cessna isn't going to give or sell the drawings for that thing so you'd be guessing at which stainless it might be.

Long live homebuilts!

Dan

Simple to send it off to a lab and get that spec for a couple hundred bucks at most.
 
The problem is the legalities associated with making parts for certified airplanes. You can do it IF you have the technical specifications. But Cessna isn't going to give or sell the drawings for that thing so you'd be guessing at which stainless it might be.

Long live homebuilts!

Dan
According to the Cessna Aircraft Company Single Engine Structural Repair manual:

The firewall is constructed of 0.016 inch, 18-8 corrosion resistant, annealed stainless steel sheet
 
I would not have waited 3 months...

That thing would have been fabricated the next day...:yes::idea:

And who would return a home made part to service ? dumber than chit with out all the blue prints and spec, that Cessna is not giving away.
 
The bite comes from the fact that when you need one of those old, out of stock parts, someone has to set up tooling to make one. Short production runs cost big bucks and they pass the cost on.

About ten years ago I ordered a cabin heat box for a 152. Price back then was $1200.

Edit: If the dies for a stamped part are no longer available you got a problem, Houston.

Cessna has hundreds of this type of parts in stock, I don't understand the year wait. These are not a stamped part. A simple sheet metal break will be the most you will need.
 
And who would return a home made part to service ? dumber than chit with out all the blue prints and spec, that Cessna is not giving away.


What bad firewall..:dunno:........:wink2:.....;)
 
Cessna has hundreds of this type of parts in stock, I don't understand the year wait. These are not a stamped part. A simple sheet metal break will be the most you will need.

Order one and tell me how quick you get it.
 
The problem is the legalities associated with making parts for certified airplanes. You can do it IF you have the technical specifications. But Cessna isn't going to give or sell the drawings for that thing so you'd be guessing at which stainless it might be.

Long live homebuilts!

Dan

They do on a daily basis. All you need is a memo from Cessna that says what it's made out of. They usually give instructions on forming and what to final heat treat to if required.
 
177B, unknown year

The Cessna Structural Repair Manual (SRM) does apply.

the one in the link may not apply, but there is one for the 177.

The 100 service manual also has a structures chapter
 
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The Cessna Structural Repair Manual (SRM) does apply.

the one in the link may not apply, but there is one for the 177.

Click the link. It doesn't apply

SINGLE ENGINE
MODELS 172, 182,
T182, 206 AND T206
1996 And On

There is no firewall material data in the 177 structural repair section.
 
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Click the link. It doesn't apply

SINGLE ENGINE
MODELS 172, 182,
T182, 206 AND T206
1996 And On

There is no firewall data in the 177 structural repair section.
I saw that … see the previous post.
 
Cessna has hundreds of this type of parts in stock, I don't understand the year wait. These are not a stamped part. A simple sheet metal break will be the most you will need.

Nope - they had to contract it out to one of their vendors. When we ordered it in late Jan 2013, we were given a two month lead time. When that time came and went, we were told that the vendor had a "tooling problem" and that it would take a few more months.

We got that run around until the end of October, at which point we gave up on Cessna and eventually found a shop that could build us one from scratch. The plan was to send them the entire firewall assembly, and they would repair/replace parts as needed and send it back to us with the necessary approvals.

From that point on, it was a matter of my mechanic finishing up the projects he was working on so that he could bring my plane back into the shop. We were a week away from that when the part arrived unexpected from Cessna. We had not heard a peep from them since the end of October.
 
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And who would return a home made part to service ? dumber than chit with out all the blue prints and spec, that Cessna is not giving away.

Are you telling me that YOU have never field fabricated an aircraft part..:dunno:
 
And who would return a home made part to service ? dumber than chit with out all the blue prints and spec, that Cessna is not giving away.

You're kidding, right? How do you think all the experimental planes are classified?

Sounds like you need to go take Mike Busch's maintenance seminar. He goes over owner produced parts quite extensively.

You can legally take the old firewall off. Hand it to a machine shop and say, "Make me one just like this." They use the damaged one as a template to fabricate the new one.

You hand it to your A&P and he installs it.
 
You're kidding, right? How do you think all the experimental planes are classified?

Sounds like you need to go take Mike Busch's maintenance seminar. He goes over owner produced parts quite extensively.

You can legally take the old firewall off. Hand it to a machine shop and say, "Make me one just like this." They use the damaged one as a template to fabricate the new one.

You hand it to your A&P and he installs it.
You best read what it requires to legally qualify a owner produced part for a production built aircraft.
The FAA can and with reason, cause you to prove it was built exactly the way the manufacturer built it.
 
You best read what it requires to legally qualify a owner produced part for a production built aircraft.
The FAA can and with reason, cause you to prove it was built exactly the way the manufacturer built it.

Ah, you mean AC 43-18, FAR 21-303 and the like.

Been there, done that!
 
You best read what it requires to legally qualify a owner produced part for a production built aircraft.
The FAA can and with reason, cause you to prove it was built exactly the way the manufacturer built it.


Do I need the manufacturer's blessing for an owner produced part?

Do I need the manufacturer's production drawing for owner produced part?

Does the owner have to physically build the part?
 
Do I need the manufacturer's blessing for an owner produced part?

Do I need the manufacturer's production drawing for owner produced part?

Does the owner have to physically build the part?

The FAA won't even consider any owner built part if the part can be bought.

READ the AC.
 
The AC says:

(1) The product must conform to its type certificate (TC). A product conforms to its TC when its configuration and the components installed are as described in the drawings, specifications, and other data that are part of the TC, which includes any Supplemental Type Certificates (STC), Airworthiness Directives (AD), and field approved alterations incorporated into the product.

end quote

to maintain production built aircraft as airworthy, it must be in it's proper altered condition, For that you must show that the components installed are as described in the drawings,specifications, and other data that are part of the TC, which includes any Supplemental Type Certificates (STC), Airworthiness Directives (AD), and field approved alterations incorporated into the product;

Show me how to prove that on owner produced parts with out some data on how the part was built.
 
The AC says:

(1) The product must conform to its type certificate (TC). A product conforms to its TC when its configuration and the components installed are as described in the drawings, specifications, and other data that are part of the TC, which includes any Supplemental Type Certificates (STC), Airworthiness Directives (AD), and field approved alterations incorporated into the product.

end quote

to maintain production built aircraft as airworthy, it must be in it's proper altered condition, For that you must show that the components installed are as described in the drawings,specifications, and other data that are part of the TC, which includes any Supplemental Type Certificates (STC), Airworthiness Directives (AD), and field approved alterations incorporated into the product;

Show me how to prove that on owner produced parts with out some data on how the part was built.


It is a factory part that was duplicated by reverse engineering, that's how it was established as eligible.
 
Show me how to prove that on owner produced parts with out some data on how the part was built.


As Henning already pointed out, we can subcontract the reverse engineering. If we have a lab tell what its made out of, for a flat sheet metal part that's about all you need. Rockwell hardness test and conductivity are popular and can be done at many MRO's.

You could easily remove the firewall and send it to a heavy sheet metal repair station for a duplicate, preferably without any holes in it. I'd want to transfer the holes myself.

Usually when a repair station does these kinds of owner produced or local produced parts that are consumed in a sheet metal repair, they will get two or more parts made, incase they mis-drill or somehow botch the first attempt at installation.
 
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As Henning already pointed out, we can subcontract the reverse engineering. If we have a lab tell what its made out of, for a flat sheet metal part that's about all you need. Rockwell hardness test and conductivity are popular and can be done at many MRO's.

You could easily remove the firewall and send it to a heavy sheet metal repair station for a duplicate, preferably without any holes in it. I'd want to transfer the holes myself.

Usually when a repair station does these kinds of owner produced or local produced parts that are consumed in a sheet metal repair, they will get two or more parts made, incase they mis-drill or somehow botch the first attempt at installation.
And how is that certified? and how do you gain approval by the FAA?
 
And how is that certified? and how do you gain approval by the FAA?


Why would I need additional FAA appoval if we have already have proven it's the same part?



If we sent the original firewall to Joe Blows Sheet Metal repair station and he sent us back a hole-less firewall with that 90 degree bend and a C of C that said it was made of the same material and dimensions as the part they received, what more do you want? A field approval? Coordinate that with the FSDO of your choice. A DER? Same deal.
 
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There is a lot of misconceptions about Structural Repair Manuals being FAA approved, most are not. Engineering guidance emails and memos from an OEM are also not FAA approved, unless it actually says it is somewhere.
 
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