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ADS-B paperwork?

bob turner

Registered User
A buddy came to my hangar with a 337 asking my advice.

He said:

1. Installing the GDL-82 is a minor alteration. Garmin has an STC for a Mooney.

2. The FAA has said that a 337 must be filed with an ADS-B installation.

I was unable to advise him - I have yet to do such an installation. My initial impression was - if it is major, you need approved data for a Cub, not a Mooney, and murtherfore, if it really is a minor alteration, you should not file a 337.

Enlighten us?
 
Didn't do a 337 when I installed my Garmin GTX 335 with integral WAAS GPS and ADS-B out. It was a transponder swap.
 
Read Part 43 Appendix A. Also when you swap a new 91.413 check is required to be recorded.
 
I'm not telling anyone else what to do , I myself file a 337, log entry and in this case have the TXP checked and a logbook entry for that. Also include a statement of the flt check in the log book entry. I believe this will get to be a can of worms with many different approaches to it, but if one were to get into a jam over its use in the field and the FAA investigates and no IA signature or 337 it will get much more complicated and expensive than just getting it signed off to start with.my 2C only.
 
I believe Pete posted the document I read and have used. They want a 337 filed with the settings used for the install and if you don't have the test equipment and use a flight test to verify another 337 when it passes.
 
The red tape is staggering. The reasonable man would think that passing the flight test for the rebate would be enough.

I believe Pete posted the document I read and have used. They want a 337 filed with the settings used for the install and if you don't have the test equipment and use a flight test to verify another 337 when it passes.
 
The red tape is staggering. The reasonable man would think that passing the flight test for the rebate would be enough.
You're catching on Eddie. When you spend a lifetime in the cockpits of military or airline planes, you don't get exposed to the inner workings of the FAA as much as you think that you have been. This is part of the reason that those of us who are retired from those professions as well as those positions which are outside the cockpit welcome the E-AB no electric route. We finally have the opportunity to raise our middle finger in the direction of the FAA without repercussions.
 
Does anyone even review 337s that are sent in or do they just file them? I use my middle finger with alot of Feds.

I filed the performance report in the log showing a pass with the original 337. That's all they get from me.


You're catching on Eddie. When you spend a lifetime in the cockpits of military or airline planes, you don't get exposed to the inner workings of the FAA as much as you think that you have been. This is part of the reason that those of us who are retired from those professions as well as those positions which are outside the cockpit welcome the E-AB no electric route. We finally have the opportunity to raise our middle finger in the direction of the FAA without repercussions.
 
Does anyone even review 337s that are sent in or do they just file them? I use my middle finger with a lot of Feds.
In the old days when they were sent to the FSDO, your PMI reviewed them before sending them to OK city. If they didn't like them, they had 30 days to get back to you for corrections. Now? I suspect that they are just filed.
 
Steve - thanks. I just read all of that.
It says: once a system is approved by STC on one aircraft, it becomes an approved minor alteration on another.
A 337 is required.
Then it gives a logbook and AFM entry.

I suppose we just follow it to the letter - but I have for years thought that one could not use a 337 for a minor alteration.

So now this single form is used for:
1. Major repair
2. Major alteration using approved data
3. Major alteration using STC
4. Major alteration via field approval
5. Minor alteration when adding ADS-B, assuming it was STC'd on a different manufacturer's aircraft.

They need one of those 350 page ACs to explain all this - and mechanics need a law degree?
 
Here we go - I was hoping I wouldn't have to do this:


FAA Memorandum of March 2, 2016

FAA Policy for installation of ADS-B – 5 pages long. Clear as mud.

Here is my take: please note that the copy function on my computer screwed up the paragraphs below - they were a,b, and then c thru i. I cannot edit them!


  1. and b. Equipment must be TSO

  1. Installer must have a “statement of compliance”
  2. Installer and owner must have a document from the STC holder identifying the aircraft receiving the installation.
  3. Must hook it up correctly
  4. Must hook it up and program it correctly (6 categories).
  5. All must be in accordance with 14 CFR sect. 43
  6. Must verify operation – flight or ramp test.
  7. Documentation required:

Must submit a 337. Block 8 must state, along with the obvious make and model information , “ The installed ADS-B OUT system was shown to meet the equipment performance requirements of 14 CFR sect. 91.227”.

Also note this exact same statement must be in the aircraft permanent records, which I would interpret to mean the airframe logbook. One could say the 337 was part of the permanent record, but why push it?

The memo answers questions:

Can an ADS-B system that does not meet requirements be installed? Answer – YES – and it looks like the field approval process is the way to do it.

Do you need an AFM revision? Again, YES. It does not need FAA approval; you merely add the following statement:

“The installed ADS-B OUT system has been shown to meet the performance requirements of 14 CFR sect. 91.227.”

This one is tricky – my avocation is reading law books. This is the best I can get out of this one:

The holder of the ADS-B Type Certificate can make minor alterations.

An example: The equipment is STC’d for a Mooney. To put it in a Cub involves a minor alteration to the STC.

But to do that, the holder of the TC needs to get a “method acceptable to the FAA for approval” before submitting the 337.

Finally, there is a helpful chart at the bottom – the FAA loves these charts, but as an engineer and attorney, they make my head hurt. Here, again, is my take:

TSO? Yes. Then is there a “Compliance Statement?” Yes. Then can we avoid major stuff like antennae in pressurized hulls? Yes. Are we going to use the TC holder’s instructions? Yes. Then we can install it. Any deviation from that requires a field approval.

Summary? A 337 and AFM revision are required. It is a major alteration by definition, but the change from Mooney to Cub is a minor alteration. That minor alteration must be approved by the FAA – presumably the holder of the TC has done that. Probably should enter a statement in the airframe log matching the one on the 337.
 
I believe Pete posted the document I read and have used. They want a 337 filed with the settings used for the install and if you don't have the test equipment and use a flight test to verify another 337 when it passes.

I did 2 337s for my install. One for the STC and the other for the flight test. Samples provided by the manufacture. Pretty easy. Took 15 min.
 
My understanding now is that this is a minor alteration for non-pressurized certified aircraft. IA signature in logbook. No 337.
 
My understanding now is that this is a minor alteration for non-pressurized certified aircraft. IA signature in logbook. No 337.
Please explain. Have one that was installed by persons unknown and no logbook entry or 337. Was going to do a 337 and then flight test and do another one after it passes.
 
I’m not an A&P or IA. But I have two close friends who are. One is also a DAR and an encyclopedia of FAR. The bottom line I’ve been told is “if there is an STC, then a 337 must be filed.”

In a world where an intercom installation requires a 337 it’s hard to believe one is not required for ADS-B.
 
Every ADSB out installation I’ve done I’ve filed a 337 following the guidance in the FAA memos or the STC instructions. By definition, an STC is a major change in type design and therefore follows that it has to be a major alteration.

The early instructions for the SkyBeacon made no mention of the airborne test. I installed several with no flight check requirement based on those STC instructions. They have since revised the instructions so now a flight check is required if you don’t have the ground test equipment. The entire ADSB thing is BS! Sure wish I didn’t live adjacent to rule airspace so I wouldn’t have to worry about big brother watching!


Sent from my iPad using Tapatalk
 
The uAvionics stc that came with my tailbeacon is for the Cessna 172 series.
But it came with this letter.

ads--b letter.jpg

This is how my IA wrote up the 337.
ads-b 337.jpg
 

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This was discussed at coffee. Guy showed me this article. I've always thought that no 337 was required for minor mods. Maybe it's the STC that requires it but I don't see that on Uavionix site.
New FAA Policy Simplifies ADS-B Installations | Business Aviation News: Aviation International News (ainonline.com)
That is 2016 info where the ADS-B unit does not have to be STC'd for ever specific model it is to be installed in. The same unit can be installed in like model of the STC. Wish they would do that with props and other stuff that is pretty common sense but of course they mandated the ADS-bB requirement but couldn't fulfill their end on the approvals so they circumvented it.
 
That's true, but if you can show that an STC installation is in fact minor, then you do not have to buy the STC - just make a logbook entry. Windshield visors come to mind.

But they made special rules for ADS-B. Once a special rule is in effect, you are stuck. They could make a special rule for intercoms, but so far they haven't.
 
If the install was a minor then why would the item require an STC? If you add or change an item and that function does not fall under the description of 'Major modification' in Part 43 then I can't see how it would require an STC and/or a 337. Think about something like seat belts. If the install does not require cutting, drilling, or welding of structure and the belts are TSO'd, just install them and do your log entry. As for my earlier post, any item that is STC'd requires a 337 be submitted to document it in OK City. I'm sure DGA or someone on his level can find exceptions and show them in the fed paperwork, but I'll stick with my initial claim. Web
 
If the install was a minor then why would the item require an STC? If you add or change an item and that function does not fall under the description of 'Major modification' in Part 43 then I can't see how it would require an STC and/or a 337. Think about something like seat belts. If the install does not require cutting, drilling, or welding of structure and the belts are TSO'd, just install them and do your log entry. As for my earlier post, any item that is STC'd requires a 337 be submitted to document it in OK City. I'm sure DGA or someone on his level can find exceptions and show them in the fed paperwork, but I'll stick with my initial claim. Web

I've often questioned that myself. I think the reason for the STC for things that are minor alterations is the only path to getting PMA approval to sell the parts. Without some certification basis, under Part 21 they can't issue a PMA for the part and without PMA it isn't legal to sell to anyone if it is anticipated that the part will be installed on a certified aircraft. The STC gives them the certification basis. That said, I wonder how they can even get the STC as FAA Order 8110.37 DER Handbook expressly prohibits a DER from issuing an 8110-3 for a minor alteration. Most STCs are all done with DER data, so I don't know how they actually get to where they can issue the STC. In short the idiot lawyers that write the FAA rules have no idea how it impacts us in the field. I concure with Wire that anything installed that has an STC should be done with a 337. I would also say that if something was installed using a 337 and is subsequently removed, there should be a 337 indicating the removal of that item. Kind of like an accounting system. I went and did an records review on a G3 years ago. Based on the paperwork and 337s, that airplane still had 3 different interior STCs installed. None of the 337s indicated that the prior interior stc was removed! I see this all the time with avionics. Looking at the paperwork, I've seen airplanes that on paper still have Loran andmaybe 3 generations of GPSs still installed and of course nobody has done a Weight and Balance update (or the owner lost them) for any of the installations. It is unfortunate, but there are a lot of lazy A&P/IAs out there and they have no idea how to do paperwork.
 
Just another rabbit hole to plummet into. Years ago during proving runs we were at dinner with 2 FAA types. After a beer or two, the senior inspector said that he would bet his retirement that it is impossible to fly a legal flight, and probable that the vast majority of aircraft could be found to be operating contrary to FAR’s if someone looked hard enough. Not just limited to light aircraft, but transport as well. I flew a jet that had triple FMS installed under an STC, and when it went back for an inspection to the manufacturer, they updated them with a service bulletin that applied to factory installed units. When I called them and questioned them about how they did this, they promptly sent a letter that the aircraft was unairworthy and a tech was enroute to our facility to fix the problem. I happen to know that there are other aircraft in the same situation that were never addressed. I could tell you stories all day about factory new aircraft with serious paperwork issues. But alas, I’m retired, the aircraft are someone else’s problem and they fly just fine…..
 
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