Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here


How do aerospace manufacturing companies certify their processes with the FAA?

How do aerospace manufacturing companies certify their processes with the FAA?

How do aerospace manufacturing companies certify their processes with the FAA?

As we all know, the FAA needs approved process specifications for mass produced parts used on multiple aircraft. I wrote a little bit I know about this.

Process Specifications are critical for a product's consistent quality, and thus 14 CFR compliance and certification.


However, can you share how companies go about getting these process specifications and fabrication methods certified with the FAA?

Aerospace Stress Analysis and FEA Courses
Stressing Stresslessly!

RE: How do aerospace manufacturing companies certify their processes with the FAA?

I am not quite sure what you are after here, in the past you would develop a process , draw up a process specification, then you or a DER would submit it to the EMDO for review. If the FAA approved it, you would then do a controlled run of the process under FAA scrutiny. (Conformity review. ).

You are judged not by what you know, but by what you can do.

RE: How do aerospace manufacturing companies certify their processes with the FAA?

Initial documentation/qualification of a controlled manufacturing process used in the production of a vehicle being certified is just the first step. When the QA of a product is based on using a controlled process, it is necessary to ensure that the personnel performing the process are properly trained/qualified, and the tools/equipment being used meet tolerance/calibration standards.

One good example I recall from a NASA program I worked on a few years back involved a controlled process used to crimp electrical connector pins on the end of wires. Being a NASA program, everything was done by the book. When the electrical tech assigned to do the work discovered he was not certified to perform this specific process, he brought it to the attention of his manager. The manager tried to find someone else in the facility with the proper certification to perform the crimping process, but there was no one available. Due to a tight schedule, an electrical tech having the necessary certification was flown in from another facility to do the work. But when this tech started the job, one thing he did was check that the calibration of the crimping tool being used was current, and it was not. There was no other calibrated crimping tool available in the facility, so one had to be shipped overnight from another facility. In the end, the crimping of a couple dozen connector contacts was performed in full compliance with process requirements, as it should have. But it took several extra days and substantial added expense.

RE: How do aerospace manufacturing companies certify their processes with the FAA?

Great story. Makes me think the manager didn't have a training budget to get the tech qualified for the process, even on a part they planned to have on the assembly. There, trimmed the fat!

I'm not sure I understand the motivation behind your question. Are you looking to learn about it as a new subject to you, or to write about it as an expert with years of experience in the field of process control?


RE: How do aerospace manufacturing companies certify their processes with the FAA?

Quality and reliability of the finished parts cannot separated from the manufacturing processes.

I don't know much about airframe OEM manufacturing approvals, but I know with airplane replacement and after market modification parts the FAA MIDO (Manufacturing Inspection District Offices) has to approve who makes what aircraft part how.

I can make a part to repair an airplane I operate (as a licensed mechanic), but I cannot sell that part as an airplane part.

A lot has to do with traceability of a part.

I lived through what follows:

I could write a company EO to have a maintenance vendor take a bunch of wires, connectors, and pins to assemble a wire harness in an airplane to implement a modification.

I couldn't send them a company DWG and tell them to fab harness DWG-501 assembly for the same modification because they aren't a parts manufacturer approved by the FAA MIDO to make DWG-501 assemblies.

They were only approved to repair airplanes (typically a under CFR Title 14 part 145).

However if in the course of maintaining the airplane they needed to manufacture a repair part, they could.

The company that developed and approved the mod held the Supplemental Type Certificate that allowed us to consider their mod part of the certificated configuration of the aircraft it was installed on.

If they coordinated with the FAA MIDO and gave a 3rd party kit fabricator a PMA assist letter, and they got PMA approval, we could use that 3rd party fabricator to make those kits for us as approved aircraft parts.

The FAA MIDO made sure the fabricator used the same tooling, standard practices and had adequate QA process to make essentially the same part that could be assembled in the airplane by licensed airplane mechanics using similar tooling, standard practices and an adequate QA system.

Had enough?

It actually all makes sense at some level, but it's not always intuitive. There are a LOT of seemingly nuanced rules and exceptions. Every one operates under a different part of the regulations and consequently is allowed to exercise different privileges and responsibilities.

My posts reflect my personal views and are not in any way endorsed or approved by any organization I'm professionally affiliated with.

RE: How do aerospace manufacturing companies certify their processes with the FAA?

Great comments.

From a structures stand point, we typically ensure there is a CPTC from materials allowables, testing and analysis standpoint ensuring compliance with Part 25 regulations.

I know a little as a stress guy but not enough from a manufacturing engineering stand point or QA standpoint.
For example process specifications and certified bonders (this ties into the NASA example above, the bonders must be certified) on an assembly line involving structural adhesives. There are company internal QC procedures and batch lap shear testing involved in ensuring the a minimum strength of the adhesive every time the adhesive is mixed.

But I am not sure how this process is certified with the FAA, or is it? Do they submit this adhesive mixing and quality control process paperwork to the FAA to get some kind of approval that says, yes we approve your process to make parts using that adhesive that are installed on an aircraft? Do they have an FAA witness on site to look at this process to give this approval?

What about other parts that are manufactured such as composite or metal primary structure parts?

How does a particular aerospace manufacturing company go about getting their fabrication methods certified with the FAA saying this is how we will make this floor beam or stringer, you the FAA approve our process to ensure compliance? What does compliance with the FAA regulations mean in terms of a manufacturing processes making parts such as a floor beam or a stringer or any other part that would eventually fly on an aircraft?

Aerospace Stress Analysis and FEA Courses
Stressing Stresslessly!

RE: How do aerospace manufacturing companies certify their processes with the FAA?

I think your starting point will be FAR part 21. Also go to FAR 25.613 and read all of the related advisory material on the subject. Of which there is a lot.
Especially when you include the associated policy letters and other miscellaneous guidance. Sorry I don't know how to shrink it down for you.

Yes, there are inspections, but of course it's much more than just a FAA inspector coming from the MIDO one day and walking around. What you really have to do, to start the process, is apply for a production certificate (or maintenance certificate as the case may be). Then the wheels start turning and everything you do can come under scrutiny, especially the means by which you document that you have done what you are supposed to do. And yes, WHAT you intend to do does have a bearing on the regulation of the process you use to do it. The qualifications of persons doing each task also figure into it, but also consider that other individuals in your company will have to have authority and responsibility to represent the interests of safety at many points in the production process. This reduces the burden of the FAA to examine every release certificate that your company issues (and the ream of paper that says that every screw and drop of glue was installed properly). It really is a matter of self-examination in excruciating detail.


RE: How do aerospace manufacturing companies certify their processes with the FAA?

Thanks SparWeb. I think its starting to make sense now, I was researching this topic a bit and I came across that any reputable aerospace manufacturer would go through the AS9100 certification, which is the certification for quality of the products produced and therefore compliance with the strict FAA regulations of manufacturing processes and quality of the final products.

Like you said, this would take a lot of burden away from the FAA because my guess is this type of certification would also include ODA units of their own companies assuring quality.

Then it would certainly be a lot of self regulation ad record keeping, and an audit would definitely severely penalize companies that do not follow the procedures.

With smaller suppliers that are not large enough to go through AS9100, the onus would probably fall on the ODA units, or the respective units answerable to MIDO audits, to check the quality and process specifications of these small suppliers for compliance.

I am probably simplifying this a little too much based on my own limited understanding, but I hope I am on the right track of thinking.

Aerospace Stress Analysis and FEA Courses
Stressing Stresslessly!

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close