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Installation Certification by AD

Installation Certification by AD

Installation Certification by AD

Anybody familiar with a process that automatically certifies an LRU P/N for installatiion on an aircraft if an AD requires the installation of that P/N in place of an existing P/N?

One of our vendors claims the process exists, but wasn't able to explain it.

RE: Installation Certification by AD

Is the new part number TSOed?

Is it approved for the application by the OEM?

RE: Installation Certification by AD

it sounds to me as though you want to replace a piece of equipment (on a plane that isn't covered by the AD) with the new (AD'd) piece of equipment ?

it's easy to say that if the equipment p/n is installed already then why not.  but maybe there are secondary issues involved with the substitution (a different software).  maybe ask the OEM why your s/n isn't covered by the AD ? (that sounds like an innocent enough question)

RE: Installation Certification by AD

The proposed AD says you must incorporate a certain manufacturers Service Bulletin (software upgrade) that rolls the P/N of the unit to a new number.

The unit currently currently installed on the aircraft is certified for use on the aircraft by an STC.

The new post mod P/N is not listed on the aircraft's TC and is not listed on any of the STCs that were the original approval basis for their installation.

This particular OEM does obtain FAA TSO approvals for their units.

RE: Installation Certification by AD

One more item, the effectivity on the original installation STCs is by aircraft model type, not by aircraft serial number.


RE: Installation Certification by AD

I would contact the FSDO and the FAA guy listed on the AD as a point of contact, explain the situation, and ask for an AMOC letter. ("Alternate means of compliance"). Make sure you have the SB info & so forth in front of you.

RE: Installation Certification by AD

Can you go back to the original holder of the STC and see if he/she has updated the STC to include the new post mod serial numbers?

RE: Installation Certification by AD

If your make, model and aircraft serial number is not listed in the AD, then the new part number is not normally eligible for installation.  Now, if the OEM feels the new part number is ok for installation on your aircraft, they can make it eligible for installation through the minor change process for the STC.  There are other ways to have the new part number added; for example, they can generate a Service Bulletin.  

What is the AD number?

RE: Installation Certification by AD

The STC holder is not normally the OEM.

As I understand the OP, the component was ADDED to the aircraft in question, by the STC process.

I would be surprised if the holder of the STC has not developed a revision to the ICAW to reflect the new,improved version of the component (by p/n)and mod status.

After all, they are now holders of an STC that involves installing a component that has a "drop dead" airworthiness directive on it.  

Not much money making potential in that!  

RE: Installation Certification by AD

thruthefence, you are correct.  

The OEM isn't always the STC holder.  Where I said "they" I should have said the STC holder.

I am assuming when you say ICAW, you mean instructions for continued airworthiness (ICA).  See FAA Order 8110.54 for further clarification.  Regarding installation approval, you should see Title 14 Code of Federal Regulations, part 21 for the requirements for installation eligibility on a type certificated product. Installation eligibilty for an STC holder, not a Production Certificate (PC)holder, requires Part Manufacturing Approval(PMA)for the part number in question.  The PMA supplement lists the eligible aircraft models.  While ICA should reflect the part numbers as you have indicated, the approval basis is the PMA supplement.


RE: Installation Certification by AD

As The developer of an STC, You do not need a PMA, if you do not manufacture the part. If, for example you wish to install a 100 Amp alternator on a small aircraft that is currently approved, under it's type certificate, for a 60 amp alternator, you merely have to work out the installation to insure the airworthiness of the aircraft is not affected. You source "your" alternator from an approved vendor. They have done the legwork on the approval of the alternator itself. Any bracketry, fittings, or wiring harnesses would in fact have to be PMAed, with attendant traceability on materials, approved drawings, and inspection of the final product. Your job is to design & carry out an installation, that does in fact meet part 21 requirements, among others.

I feel the problem facing the original poster can only be resolved by amending the paperwork issued by the holder of the STC, to approve the installation of the "new, improved" model.

The problem may be the STC holder is no longer available,ie gone out of business, or has "sold" the stc to a another party, Or surrendered it.  

RE: Installation Certification by AD

Interesting perspective.  

But, the only acceptable methods for producing parts to be installed on a type certificated product are as follows:  

First, it can be an owner produced part (but not sold over the counter). For this, you won't need to produce the part under an FAA approved quality system.  

Second, the part is produced and "sold over the counter".  The second method requires an FAA approved quality system (AKA a PMA part).  

Third method is to produce a TSO'd part and then receive a TSOA ( FAA approval for the part).

Fourth, produce the part under an FAA approved production certificate (PC).  This would apply to OEM's such as Cessna, Boeing .......  

In a nutshell, if you produce a part for installation on a TC'd product and intend to sell it on the street, you must have some form of FAA approval.

Now, for the original question that started this thread, it seems to me that the person was purchasing the part (not owner produced).  Thus, the part will need to be produced under an FAA approved quality system.  He indicated that he was unsure of the installation eligibility for a certain aircraft.  An AD does not automatically approve parts for installation on aircraft not listed in the AD.  He would be well advised to talk to the OEM or STC holder to verify installation eligibilty.   


RE: Installation Certification by AD

We are exactly on the same page.

However, I don't think the OP wants to "manufacture", or certify, a part.

As I understand the OP's question, he has a component, installed under an stc, ie not original, OEM installation.

Let's assume, for the sake of argument, the equipment is a "Whiz-Bang Navmaster 500" PFD, p/n 500-1; a cutting edge product of the giant "Navmaster corp". This model & p/n Navmaster PFD is original equipment, and supported by an OEM (and the vendor, Navmaster) in several models of the oem's Certificated, current production aircraft.

A large avionics shop, "Peckerwood Avionics" sees the popularity & usefulness of the new "Whiz-Bang Navmaster 500", and approaches the vendor (Navmaster corp) for ten ship sets of TSO'ed PDF's, p/n 500-1. Business is business, after all, so the deal is closed. "Peckerwood" puts it's guys to work, for a STCed installation on a "Belchfire Flite-King" a popular, but out of production aircraft. They see a market for replacing the "steam gauges" in this fleet of 5000 "still on the books" aircraft. Peckerwood's engineering dept makes up the drawings, their on staff DER signs off on the changes to the Instrument Panel, it is approved by the Feds, and an STC issued. They sell eight STC'ed installations, and are preparing to order ten more shipsets.........

Then Navmaster issues a mandatory service bulletin. There have been "Ghost images" when operating in the night vision mode, and false altitude readings. They send out SIM cards with software updates,to all operators, but in 15% of the fleet, the errors remain. One aircraft, an OEM installation, has a near-miss due to bad altitude information. The OEM, who has aircraft in production, insists the vendor fix the problem. Lot's of bad publicity affecting sales. The vendor, now decides to recall all units from the field, upgrade some hardware as well as software, re flash the chips, whatever; & rigoriously test the units, and send them back under a new P/N, 500-3........

In the meantime, another Navmaster equipped aircraft, while busting minimums takes out the approach lights at BMF, in a "reportable accident" The NTSB & the FAA are now involved, and after being satisfied Navmaster is on the right track, issue an AD note, requiring the "-3"  

Meanwhile times are bad at "Peckerwood" avionics, the crash of '09 has hit them hard. They have laid off half their staff, and worse, they are on COD with the Navmaster Corp!!

The operators with the "Peckerwood STC" are left out in the cold. They can't even pay out-of-pocket for a p/n -3, and legally install it!! The AD note is very specific!

The operators all get together, (one of the operators has a "Blog", "Peckerwood STC sucks") and they retain council, who sues "Peckerwood Avionics".

To Late!! They have declared bankruptcy, and the disgruntled, laid off employees have stolen all the shop equipment and supplies!

And that's why I think the AMOC letter from the Feds, would be a good idea.

Happy New Year, everyone!!

RE: Installation Certification by AD

... LOL ...

You are probably right on the money....

The only flaw I can see is that the company (Peckerwood) who wants to buy the Navmaster upgrade doesn't have an aircraft model listed in the AD. As such, they can't request an AMOC because the AD doesn't apply to the aircraft in question.  

It would appear that Peckerwood is truely up the creek without a paddle.  But wait, Peckerwood hires I. R. Smart, a System and Equipment DER.  Mr. Smart approaches the FAA and requests a deviation to the original STC.  He demonstrates that the upgraded Navmaster is a vast improvement and enhances safety.  The folks at "Fed World" are happy, Peckerwood is happy and the aircraft owner flies off into the sunset, knowing he has the safest nav system around.


RE: Installation Certification by AD

"As such, they can't request an AMOC because the AD doesn't apply to the aircraft in question"

Maybe I'm reading the wrong thing into it, but I "assumed" (you know what that means!) that the AD was against a "component" such as the silly PFD in my example, and not a specific airframe.

Like you, I'd like to know the specific AD number,to comment with a little more clarity.

"aircraft owner flies off into the sunset, knowing he has the safest nav system around."

And this is what we all strive for, for sure!!


RE: Installation Certification by AD

The op isn't giving enough info. What is the effectivity of the AD, by aircraft, or by appliance? If the AD says that the effectivity is component XYZ regardless of aircraft installed on, and to replace component XYZ with component ABC, then the AD is the approved data for the installation and since the AD is a regulation (Part 39), the installation is a minor alteration requiring only a log book entry.

David Schober

RE: Installation Certification by AD

One other comment, since it looks like the component was installed via STC, under the requirements of Part 21, the STC holder needs to revise the STC to include the new part number in the STC and the ICAs for the STC.

RE: Installation Certification by AD

Another comment, under 21.303, you only need PMA if the part is produced for SALE for installation on a cetrified aircraft. If you aren't selling the part no PMA is necessary.

Typically a piece of electronic equipment will be TSO, so again, no PMA required since TSO is both a design and production approval.

RE: Installation Certification by AD

"One other comment, since it looks like the component was installed via STC, under the requirements of Part 21, the STC holder needs to revise the STC to include the new part number in the STC and the ICAs for the STC."

Exactly so.....!

I kinda get the impression that the STC holder isn't cooperating.

RE: Installation Certification by AD

maybe take out your own STC ? (to modify the STC install to the new OEM config)  

this'd mean checking how the new unit would interface with the STC, and whether the OEM rolled someother related change in their mod.

RE: Installation Certification by AD


Sorry not to have been back for a while. There have been other pressing matters.

I haven't had time to read through the responses.

Here is a link to the NPRM ->

TCAS is installed on most of our fleets by 3rd party STC. I say 3rd party because they are not the operator or airframe OEM. The equipment OEM holds the STC in most cases, but maybe not all. I believe we may have one STC in the mix thats owned by a (Designated Alteration Station) we contracted with.

I'd like to obviate STC approval, revision, amendment, change, process, if possible, because it can take so much time. Working out agreements and getting them through legal can add almost a year to even the simplest project. We're looking at an accomplishment time of 48 months.


RE: Installation Certification by AD

Ok, now it makes more sense. You have TCAS units that were installed as part of an STC. The STC calls for the TCAS unit by part number. The AD requires SB compliance on the unit that will roll the part number to one not listed on the STC. A repair station authorized to perform the AD/SB does the work and returns the unit to you with an 8130-3 return to servicee. Since the part number no longer matches the STC, you have no authorization to install the new part number unit.

First thing, have you made comments to the Federal Register with your concerns yet? You have until 2/11/2011 to make comments. FAA will have to answer those comments prior to issuing the AD, and there is where you will get your final answer.

When you make your comments, be sure to be clear and concise on your discription of the problem. Identify additional costs that are not in the NPRM that will be required to comply. They only used 2 hours @ $85 an hour. As I see it, you have to remove the unit, ship it to the facility that can make the repairs, recieve it back into your quality system, then re-install it in the aircraft at a minimum. f additional engineering is required for the STC, there are more costs associated with that. You also have down time and lost revenue.

Another concern I have is that the NPRM states "Traffic Alert and Collision Avoidance System (TCAS) units with the part numbers (P/Ns) specified in the ACSS service bulletins identified in Table 1 of this AD". I've never seen an AD that references a vendor document to identify the units that are impacted by the AD. This makes no sense, unless the aircraft operator has the SB, he won't know that the AD impacts him. The AD should identify by part number exactly what units are impacted by the AD.

All in all, this is one of the worst proposed ADs in terms of understanding the requirements.


RE: Installation Certification by AD


I don't understand how an AMOC would help in our case.  I read through your hilarous vignett and do see where you are coming from.  It's very interesting to me personally because I have recently been wondering if there was any merit to starting a company like Peckerwood. That question is probably best left to another thread entirely.

If I had to deal with that situation, I don't know exactly how I'd approach it. It's always difficult dig out the underlying facts in hypothetical situations.

I'm an avionics engineer for the 121 world, that's just about to get my instruments rating and I'm insanely driven to buy an airplane this year.  It's obvious that a lot of small operators need help in these areas, but I wouldn't want a hobby pastime I truly love to become legal hell.  

I don't think there is any money in starting another marginal me-to 3rd party avionics company either.  There might be something in helping the Peckerwood customers, but!  They might have made marginally uninformed decisions hoping to luck out on something too good to be true, and might be hard to collect from if even if you do excellent work for them on a bail out.

Does Peckerwood go on to surrender their STC to the FAA? What they might do to support the matter?  


I am going go back to the OEM holder and in the cases where they hold the STC, see if they plan to update the STC. Good advice, thanks. I need to get it done early in time to eval what they say and comment.


I really don't like the way the AD is written either.  Listing SBs instead of explicitly listing specific part numbers will create problems going forward.  I do a lot of AD research for aquisitions on older airplanes.  In 20 years it will be impossible to determine if that AD has been complied with on a purchased aircraft, if it's not changed.  

Those SBs may very well not be publicly available 20 years from now.  I've already obtained a set and three have already been revised since the AD was drafted.  Some are SBs written for military product lines.

I do plan to recommend that we comment on the AD.  I'm still researching our own particular situation to understand what kind of obstacles we're facing, before I draft anything.           


RE: Installation Certification by AD

And sometimes, SB's are revised, often for no other reason then to correct punctuational. If the AD note doesn't say "or latest revision" for it's compliance. You may be stuck again at some later date.  

RE: Installation Certification by AD

now i'm confused (situation normal ?) ... is there an AD or are you anticipating something coming from the NPRM ?

won't the AD reference a particular a/c configuration or component ?  it sounds to me as though you have an affected a/c but you've changed the config (with a 3rd party STC), and so aren't affected by the AD ??

now if your 3rd STC isn't compliant with the NPRM, that's a different question ... if the 3rd party won't fix it, then someone else has to.

RE: Installation Certification by AD

Another thought, as written in the NPRM, it wouldn't comply with the Adminsitrative Procedures Act, as the vendor (L3 in this case) could revise the SB to include additional products and since the AD NPRM now only lists the SB and not the specific products, the requirement to modify the additional products listed in a revised SB would not have the benifit of going through the public comment and cost analysis required. The guy that wrote this NPRM is really screwed up!

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