FAA vacuum instrument replacement policy

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Walboy

Pre-takeoff checklist
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Walboy said:
I received an email from the FAA which included this:

On September 14, 2015, the FAA published policy statement PS-ACE-03-08, “Replacement of Vacuum Driven Attitude Indicators in 14 CFR, Part 23/CAR 3 Airplanes.” The policy clarifies that most vacuum driven attitude indicators can easily be replaced with new electronically driven attitude indicators utilizing the minor alteration process.

http://www.faa.gov/aircraft/draft_docs/media/PS-ACE-23-08.pdf

Can someone explain this to me and what has changed? I assumed something like this existed enabling the installation of Aspen avionics.

Further, can you remove a vacuum powered heading indicator if the attitude indicator provides directional information?

These FAA documents often confuse me more than they help.
Click to expand...

The document you link to is only a draft, with no official validity or publication date. Has anything newer been published?
 
Walboy said:
I assumed something like this existed enabling the installation of Aspen avionics.
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I can't answer your main question. I can say that the Aspen PFD and other Aspen displays are installed under an STC so nothing like the rule you linked is required.
 
Clark1961 said:
I can't answer your main question. I can say that the Aspen PFD and other Aspen displays are installed under an STC so nothing like the rule you linked is required.
Click to expand...


An Aspen PFD unit does require a backup AI indicator. In the past this was usually the vacuum based AI. From what I am reading, they are basically saying that an EFIS or PFD based AI driven by electricity and with a backup power supply can replace the vacuum AI. If this is true, then you can either replace your vacuum AI with a standalone electric powered AI providing it has a battery backup or an Aspen.

I would like to know if this is actually a policy in effect and what it means to thousands of Aspen owners. I have enough AIs...


2fb7cdeb0b5291d4d9e266421c4c06ac.jpg





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Clark1961 said:
I can't answer your main question. I can say that the Aspen PFD and other Aspen displays are installed under an STC so nothing like the rule you linked is required.
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Did you read the Policy statement? It explains that. It says the electronic gyros are not to be confused with PFDs.

When I did the Fairchild's instruments, I up graded the AI and DG with electrically driven instruments on a field approval. Now that method of approval is not required.
 
Conclusion
Based on this policy, vacuum-driven attitude indicators can be directly replaced with electronically-driven attitude indicators to enhance small aircraft safety. These alterations can be approved through the Amended Type Certificate, Supplemental Type Certificate, Amended Supplemental Type Certificate, Field Approval (337), or Minor Change processes, as appropriate. However, the intent of this policy is to communicate that most replacements can likely be done as minor changes.
 
Final Policy


Hide details for [<span class="frmsectionlabel">Policy Information</span>]
Policy Information


Policy Number:
PS-ACE-23-08
Status:
Final



Issuance Date:
09/14/2015
 
Tom-D said:
Conclusion

Based on this policy, vacuum-driven attitude indicators can be directly replaced with electronically-driven attitude indicators to enhance small aircraft safety. These alterations can be approved through the Amended Type Certificate, Supplemental Type Certificate, Amended Supplemental Type Certificate, Field Approval (337), or Minor Change processes, as appropriate. However, the intent of this policy is to communicate that most replacements can likely be done as minor changes.
Click to expand...


What do you think it means for those of us with Aspens? Can e remove the vacuum system along with the vacuum AI?


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Marauder said:
Can we remove the vacuum system along with the vacuum AI?
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As I read it, yes, but you must supply a separate battery as a back up.

My question would be, is that in its self a major alteration the electrical system.?
 
Tom-D said:
As I read it, yes, but you must supply a separate battery as a back up.



My question would be, is that in its self a major alteration the electrical system.?
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Each of my Aspens have battery backups. Over on the Mooney site, someone asked if this means they can install a Garmin G3X in place of the AI. My quess is no, since it is clearly not certified for certified airplanes.


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Walboy said:
Silly me, I just assumed the vacuum system was removed in airplanes with Aspens.



Why can't this stuff be written in plain English?



What other products are on the market that would work in a Cherokee? I don't think Dynon has anything for certificated aircraft yet, but I heard a Dynon rep at an airshow last year say they are in "talks" with the FAA as FAA has finally recognized electronic AIs are more reliable. Maybe this is a precursor to allowing more products on the market.
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I wonder if the Sandia unit is certified yet. The same for the Bendix King unit.


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Tom-D said:
Did you read the Policy statement? It explains that. It says the electronic gyros are not to be confused with PFDs..
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Please show where it said that.

The OP said that something like the rule was needed for the Aspens and I was just pointing out that Aspen was installed under an STC. No rule like that was required.

Addressing your other concern about the battery backup for the Aspens, it's covered under the STC so the question of major alteration or not is moot. Each Aspen PFD has a built-in battery and then on redundent PFD systems without a separate back-up AI there is a third battery.
 
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One key requirement is that the electrical unit fit in the same hole as The vac and otherwise not disturb the original certificated 6 pack.

Ironically I think that means that an Aspen could be installed as a minor alteration to backup a fully STC'd Aspen, and eliminate the now required vac AI.
 
Tom-D said:
Did you read the Policy statement? It explains that. It says the electronic gyros are not to be confused with PFDs.

When I did the Fairchild's instruments, I up graded the AI and DG with electrically driven instruments on a field approval. Now that method of approval is not required.
Click to expand...
Tom,

How much time/labor is involved in switching a vacuum AI over to an electric one?

I'm contemplating ditching the venture vac AI/DG for electric in the 170.
 
Fearless Tower said:
Tom,

How much time/labor is involved in switching a vacuum AI over to an electric one?

I'm contemplating ditching the venture vac AI/DG for electric in the 170.
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Well the whole job would be to remove the vac system, pump and all. I'd say about a day to swap out the vac for an electrical gyro. you'd save about 20 pounds over all.
 
Clark1961 said:
Please show where it said that.

The OP said that something like the rule was needed for the Aspens and I was just pointing out that Aspen was installed under an STC. No rule like that was required.

Addressing your other concern about the battery backup for the Aspens, it's covered under the STC so the question of major alteration or not is moot. Each Aspen PFD has a built-in battery and then on redundent PFD systems without a separate back-up AI there is a third battery.
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I don't have the time to fully explain this this morning, read the Back ground statement.
When you have a STC you are golden. this will not effect that installation.
 
Tom-D said:
I don't have the time to fully explain this this morning, read the Back ground statement.
Click to expand...

I understand that you are conceding that it didn't directly say that electronic gyros are not to be confused with a PFD. It did explain the differences.

Do you see my point? What you said was your interpretation, not the written word.
 
Tom-D said:
Well the whole job would be to remove the vac system, pump and all. I'd say about a day to swap out the vac for an electrical gyro. you'd save about 20 pounds over all.
Click to expand...
Mine still has the veturi vac system - no pump to remove and I'd probably leave the veturiis in place for appearance sake.
 
RyanShort1 said:
I'd LOVE to take the venturiis off of my bird and pick up a knot or two.
Click to expand...
Don't blame you.

Mine was painted recently and I suspect it would need some additional work on the fuselage if you removed the venturis. Plus 95 kts vs 97.....either way, its not going anywhere fast.
 
On a six hour flight with headwinds it helps


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Also, the overlap cant hit the other instruments. Some of the square ones do.
 
Nor would I want to modify my hole. That one is more of a problem than you think. If the company is out of business when the new one fails, you cant go back to the old hole shape if youve removed metal. Those panels are really expensive and hard to replace.
 
Clark1961 said:
Please show where it said that.

The OP said that something like the rule was needed for the Aspens and I was just pointing out that Aspen was installed under an STC. No rule like that was required.

Addressing your other concern about the battery backup for the Aspens, it's covered under the STC so the question of major alteration or not is moot. Each Aspen PFD has a built-in battery and then on redundent PFD systems without a separate back-up AI there is a third battery.
Click to expand...

Really guys? Comparing the Aspen, a highly integrated PFD, to a simple stand alone electronic "gyro"?


They aren't even close to being the same thing.


Even if one specific function of a highly integrated system is determined to be minor in nature how can you approve the whole potato without an STC?
 
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Fearless Tower said:
Mine still has the veturi vac system - no pump to remove and I'd probably leave the veturiis in place for appearance sake.
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One day.

Removed vacuum AI.

Remove the associated hoses and cap the open fittings.

Install wiring to electric AI and mount in the hole.

Turn-on, calibrate and placard as needed

W&B rev if required, electrical load analysis, equipment list revision and log entry.
 
bnt83 said:
Really guys? Comparing the Aspen, a highly integrated PFD, to a simple stand alone electronic "gyro"?
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Read the OP. That is where the Aspen got drug into this.
 
Walboy said:
Cap'n Ron chiming in on this topic over at the red board with pretty decent information. I think I understand a little better now.

http://forums.aopa.org/showthread.php?t=96646

Apparently, this product from Spruce is an example of what can be installed:

https://www.aircraftspruce.com/catalog/inpages/rca2600-3.php

Along with this backup battery:

https://www.aircraftspruce.com/pages/in/emergencypower/rcallenbatterybackup.php
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Those two references are not what are allowed under this new policy.

This type of instrument is the ones which can be installed as a minor.
http://www.aircraftspruce.com/catalog/inpages/castleberry300.php?clickkey=99082

This is the DG.
http://www.aircraftspruce.com/catalog/inpages/ssp-10-05077.php?clickkey=88319
 
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your incorrect tom. the rca2600 is certified and can be installed. solid state gyros are allowed under policy.
 
Let's read the last paragraph:

Conclusion
Based on this policy, vacuum-driven attitude indicators can be directly replaced with electronically-driven attitude indicators to enhance small aircraft safety. These alterations can be approved through the Amended Type Certificate, Supplemental Type Certificate, Amended Supplemental Type Certificate, Field Approval (Form 337), or Minor Alteration processes, as appropriate. However, the intent of this policy is to communicate that most replacements can likely be done as minor changes.

Which replacement will use which authorization?

I will say that this policy does not limit which type can be used, but it also does not say which authorization will be used for what installation.
 
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right in the cited document.

Electronically-driven attitude indicators include indicators​
​
that use electrical power to (1) excite an internal gyro, or (2)​
​
replace the operation of the gyro with microelectronics. Electronically-driven attitude indicators may replace the existing attitude indicators used in VFR or IFR airplanes.​
​


For part 23/CAR 3 aircraft under 6,000 pounds with vacuum
-driven attitude instruments, it is acceptable to replace vacuum
-driven attitude instruments with electronically-driven attitude
indicators under the following conditions
:
1.A single function vacuum-driven attitude indicator may be replaced with a single primary function electronically-driven attitude indicator.
A single function vacuum-driven attitude indicator may also be replaced with an electronically-driven attitude indicator
that provides a secondary (advisory) function (such as turn & slip indication).
2.The electronically-driven attitude indicator has an independent standby battery that is capable of meeting the intent of §23.1331 and§23.1353(h) to independently power the
new instrument in the event of a loss of primary electrical power. It may not acceptable to use the start battery as a backup power source for the electronically-driven attitude
indicator unless its state of charge can be verified at takeoff
.
3.The final installation and arrangement must allow for use of
partial panel techniques in the event of a loss of the electronically-driven attitude indicator source.
4.Compliance must meet all other applicable regulations
(i.e.,§§23.1381, 23.1331,and 23.1353)

To install an electronically-driven attitude indicator as a minor alteration, the above conditions and the following additional regulations must be met


so what part does the RCa2600 with backup battery not meet?
 
unsafervguy said:
right in the cited document.

Electronically-driven attitude indicators include indicators​
​
that use electrical power to (1) excite an internal gyro, or (2)​
​
replace the operation of the gyro with microelectronics. Electronically-driven attitude indicators may replace the existing attitude indicators used in VFR or IFR airplanes.​
​
Click to expand...

Well Good, but I'll wage a weeks allowance the FSDO will have a fit over adding the second battery as a minor. and some will as I did think microelectronics a PFD. which they say requires a back up battery. will require a method of approval other than a minor and a log book entry.
 
unsafervguy said:
so what part does the RCa2600 with backup battery not meet?
Click to expand...

As I've said already, they can be used, It's just a matter of do you think they can be a minor alteration.??
 
Tom-D;1898281This is the DG. [url said:
http://www.aircraftspruce.com/catalog/inpages/ssp-10-05077.php?clickkey=88319[/url]
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The DG you linked says non-TSOd.

If you are putting it in a certified airplane don't you have to use a TSO one?
 
Tom-D said:
As I've said already, they can be used, It's just a matter of do you think they can be a minor alteration.??
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i would find it hard to say that mounting the battery to the airframe and plugging in the harness supplied by the manufacturer of the certified unit could be called a major alteration.

i would agree if you attempted to use anything other than the RC Allen backup battery would be a paperwork nightmare, but this unit is exactly what this policy is about. this is in no way a PFD. it is a solid state attitude gyro. a certified electronic version of the age old spinning gyro. nothing more. this is what this policy is written to clear up.
 
unsafervguy said:
i would find it hard to say that mounting the battery to the airframe and plugging in the harness supplied by the manufacturer of the certified unit could be called a major alteration.

i would agree if you attempted to use anything other than the RC Allen backup battery would be a paperwork nightmare, but this unit is exactly what this policy is about. this is in no way a PFD. it is a solid state attitude gyro. a certified electronic version of the age old spinning gyro. nothing more. this is what this policy is written to clear up.
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we will see when the issue raises it head at FSDO.

Until you prove this is not a factor you'll get stone walled at the FSDO>
FAR 43-A (a)
(xii) Changes to the basic design of the fuel, oil, cooling, heating, cabin pressurization, electrical, hydraulic, de-icing, or exhaust systems.
 
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