AV-30C 337?

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tecillo

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tecillo
So I asked 4 different IA / a&p people and got about 4 different answers. Has anyone with and AV-30 been required to fill a 337 form? I been told no need to since it’s STC and a minor alteration. Then I heard you need an IA, then I heard you need a 337 but it can be filled out by an A&P. This would make like easier and cheaper if that’s the case. I’m pairing it with a tailbeaconx if it matters. What has been your experience?

Ruan
 
It’s a major alteration, approved by an STC, requiring a 337. An A&P can install, but an IA must approve for return to service. Another 337 will be required for the TailBeaconX unless they are on the same STC. A weight and balance revision will likely also be required.

Jesse Saint A&P/IA
 
Back in 2015 the FAA released PS-ACE-23-08, providing the regulatory framework to replace an existing vacuum-driven gyroscope with an electric/electronic unit (such as an AV-30) as a minor alteration.

Only the gyro function was allowed to be replaced, so you couldn't take advantage of the airspeed/altidude indications and remove those gauges.
 

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This kind of what I been getting, a couple of different responses, they’re both good answers and justified. Still trying to figure it out, I’m short of asking the FSDO. My luck I’ll get a 5th different answer lol thank you all
 
tecillo said:
This kind of what I been getting, a couple of different responses, they’re both good answers and justified. Still trying to figure it out, I’m short of asking the FSDO. My luck I’ll get a 5th different answer lol thank you all
Click to expand...

One answer is backed by a policy statement, that’s the only one that matters. Ignore opinions, go with the fact based one.
 
Bottom line, the installer determines whether it is a major or minor alteration.

If the installer decides it is a major alteration, it requires approved data such as an STC, IA signoff, and a 337. This is the low risk approach, so for many shops it is the default answer. If the shop has an IA, there is little downside or added cost.

If the installer determines it is a minor alteration, it does not require an IA or 337. If you find an A&P willing to install and sign off that way, the risk is on him, not you.
 
Ed Haywood said:
Bottom line, the installer determines whether it is a major or minor alteration.

If the installer decides it is a major alteration, it requires approved data such as an STC, IA signoff, and a 337. This is the low risk approach, so for many shops it is the default answer. If the shop has an IA, there is little downside or added cost.

If the installer determines it is a minor alteration, it does not require an IA or 337. If you find an A&P willing to install and sign off that way, the risk is on him, not you.
Click to expand...

What risk are you talking about? Liability? FAA action?
 
tecillo said:
This kind of what I been getting, a couple of different responses, they’re both good answers and justified. Still trying to figure it out, I’m short of asking the FSDO. My luck I’ll get a 5th different answer lol thank you all
Click to expand...
In general , you'll find any time someone makes a installation determination there will be an objective part and a subjective part. What is airworthy is a prime example: it comforms to its type design (objective part) and its in condition for safe flight (subjective part).

Same for your AV30 install. The objective side is what install guidance is selected and how it is applied. However some people dont follow any guidance or apply it incorrectly and subjectively determine how the install will be performed.

For example, a number of people subjectively believe all STCs are major alterations. However, the existing guidance does not support that conclusion. Or sometimes there is more than one guidance route to follow and not everyone wants to use those other routes.

So back to your AV30 install it will depend on what route they selected. As noted above, if you were installing it only as a replacement for a vaccum AI, then that policy letter provides guidance for a minor alteration, ie., no 337.

However, since you will interface a 2nd system to the 30 then you would need follow a different guidance route like AC 43.210 which will help determine if that install is a major change to type design, major alteration (both requiring approved data and 337), or if it is still a minor alteration. And since the tailbeacon brings ADSB into the mix there is additional guidance that must be addressed and so on.

Regardless, its not as complex as it appears and most determinations are made in minutes not hours or days unless the install is very complex. And once you inject the installers subjective side you see how you can get 4, 5, 10 different answers. Make more sense?
 
Ed Haywood said:
FAA compliance. I assume the potential consequences for treating a major alteration as a minor are more severe than vice versa.
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I gotta think as long you can make a reasonable argument why you treated it as a minor alteration you’re free any potential violation. As pointed out by @AV8R_87 there is a published policy statement, so where’s the problem?
 
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