Do I need TSOed Gyros in my PA28?

poadeleted21

poadeleted21

Touchdown! Greaser!
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Aug 18, 2011
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Seems to be a nice price gap in otherwise indistinguishable instruments, is there any requirement for me to have TSOed gyros? I'd likely replace all 6 if I could go with the non-TSOed variety.
 
bartmc said:
Seems to be a nice price gap in otherwise indistinguishable instruments, is there any requirement for me to have TSOed gyros? I'd likely replace all 6 if I could go with the non-TSOed variety.
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It's a fine line between fit and function and a major modification with instruments. I'd not try to answer this in forums, but I would call your A&P-IA's PMI to see what they think for a part 91 operator.
 
Tom-D said:
It's a fine line between fit and function and a major modification with instruments. I'd not try to answer this in forums, but I would call your A&P-IA's PMI to see what they think for a part 91 operator.
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I need to do something with my DG, it precesses a little too much for my liking. I don't really want to sit and wait for an overhaul, While I'm at it was going to stick a new TC and AI in there . Trying to do a back of the envelope calculation for parts cost. If it's a major paperwork pain, I'll just try to find overhauled TSOed instruments. After my 8 month ordeal with getting my GPS certified, I'm well aware of paperwork hell. I'm at the spot and time of year in my instrument training that we're likely to encounter actual IMC and some fresh gyros would make me feel better.
 
bartmc said:
I need to do something with my DG, it precesses a little too much for my liking. I don't really want to sit and wait for an overhaul, While I'm at it was going to stick a new TC and AI in there . Trying to do a back of the envelope calculation for parts cost. If it's a major paperwork pain, I'll just try to find overhauled TSOed instruments. After my 8 month ordeal with getting my GPS certified, I'm well aware of paperwork hell. I'm at the spot and time of year in my instrument training that we're likely to encounter actual IMC and some fresh gyros would make me feel better.
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Buy one off E-bay, send it in for overhaul, and swap it out when it returns.
 
bartmc said:
Seems to be a nice price gap in otherwise indistinguishable instruments, is there any requirement for me to have TSOed gyros? I'd likely replace all 6 if I could go with the non-TSOed variety.
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They don't have to be TSO'd, but they do have to be FAA approved. Here's how Aircraft Spruce puts it:
NOTICE! Many parts on our website are NOT FAA approved. Unless our website specifically indicates a part has a PMA (Parts Manufacturers Approval), that part may not be certified or approved for aviation use. The selling of a part should not be construed as a representation that the part is certified or approved for aviation use, nor can Aircraft Spruce & Specialty Co. include instructions for use or warnings unless provided by the manufacturer or distributor. Any concerns the purchaser may have about the suitability of a part for aviation use, instructions for use or warnings, should be promptly directed to the manufacturer.
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Ron Levy said:
They don't have to be TSO'd, but they do have to be FAA approved. Here's how Aircraft Spruce puts it:
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AS&S's statement is a CYA for them and does not answer the question of "is a TSO instrument required" there is a big issue here in as much as the electronic instruments are readily available for aircraft.

The question is, does the electronic instrument meet design criteria of the type certificate. and give the redundancy required by part 91. The FAA has not made a statement on that and probably won't
 
Tom-D said:
AS&S's statement is a CYA for them and does not answer the question of "is a TSO instrument required" there is a big issue here in as much as the electronic instruments are readily available for aircraft.

The question is, does the electronic instrument meet design criteria of the type certificate. and give the redundancy required by part 91. The FAA has not made a statement on that and probably won't
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All for not now, I found a gyro place that can turn them around in one day, and a nice guy that has a recently overhauled DG for less than the cost of an overhaul.
 
Tom-D said:
AS&S's statement is a CYA for them and does not answer the question of "is a TSO instrument required" there is a big issue here in as much as the electronic instruments are readily available for aircraft.
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I'd already answered that question -- TSO isn't required for his plane. I was trying to anticipate a question of how to tell if a part is "FAA approved," which you and I both know is a lower standard that "TSO'd," but still necessary for installation in his plane.

The question is, does the electronic instrument meet design criteria of the type certificate. and give the redundancy required by part 91. The FAA has not made a statement on that and probably won't
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Who said anyting about electronic instruments besides you?
 
Ron Levy said:
Who said anyting about electronic instruments besides you?
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no one, that is where the big controversy is these days.

Bart says
"Seems to be a nice price gap in otherwise indistinguishable instruments, is there any requirement for me to have TSOed gyros? I'd likely replace all 6 if I could go with the non-TSOed variety."

he may want to go with all glass after market instrumentation
 
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"FAA Approved" is a new one on me. Although I think I know what Ron is trying to say. I can see that a required instrument would need to have a PMA. However I have yet to find a TSO'ed or "FAA Approved" G-meter or Variometer. Yet I see them in many aircraft.

Brian
 
brcase said:
However I have yet to find a TSO'ed or "FAA Approved" G-meter or Variometer. Yet I see them in many aircraft.
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I suspect part of it is whether the instrument is required for the operation (part of VFR minimum, or IFR minimum equipment).
If the instrument is not required, you can probably put in just about anything you want.

G-Meters and Variometers are not required for any operation.
 
At least one of the Key Lime Metroliners has an AoA indicator... I noticed it on top of the glareshield.

Forgot to ask if all of them did... or if it was required...
 
If your aircraft came with Cessna gyros with cessna part numbers, can you use a century gyro, that fits the hole and does the same thing?
 
brcase said:
"FAA Approved" is a new one on me. Although I think I know what Ron is trying to say. I can see that a required instrument would need to have a PMA. However I have yet to find a TSO'ed or "FAA Approved" G-meter or Variometer. Yet I see them in many aircraft.

Brian
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A good read on FAA approval AC 20-62E
 
BartMC said
Seems to be a nice price gap in otherwise indistinguishable instruments,
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I'm really not familiar with typical PA28 documentation, and I'm not trying to be critical.

Out of curiosity, what method did you use to establish the old and proposed gyro are indistinguishable?
 
PilotAlan said:
I suspect part of it is whether the instrument is required for the operation (part of VFR minimum, or IFR minimum equipment).
If the instrument is not required, you can probably put in just about anything you want.

G-Meters and Variometers are not required for any operation.
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You suspect right.
 
Tom-D said:
no one, that is where the big controversy is these days.

Bart says
"Seems to be a nice price gap in otherwise indistinguishable instruments, is there any requirement for me to have TSOed gyros? I'd likely replace all 6 if I could go with the non-TSOed variety."

he may want to go with all glass after market instrumentation
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AFAIK, there's no TSO for glass panel displays, but they must be FAA approved to go in a Standard aircraft to replace the existing flight instruments.
 
Ron Levy said:
AFAIK, there's no TSO for glass panel displays, but they must be FAA approved to go in a Standard aircraft to replace the existing flight instruments.
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as given in the AC 20-65E, Para (a) & (b) gives several methods of approval TSO being 1 of them.

Explain why the FAA approved the glass dash in a C-182S but won't in a up grade on a 182.
 
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kontiki said:
BartMC said

I'm really not familiar with typical PA28 documentation, and I'm not trying to be critical.

Out of curiosity, what method did you use to establish the old and proposed gyro are indistinguishable?
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I was just making an eyeball observation from the pictures i see on the innarwebs that the $500 NON-TSO ed units and the $1,000 TSOed units seem strikingly similar. Nothing scientific.
 
Tom-D said:
A good read on FAA approval AC 20-62E
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While I certainly didn't read it in detail. It looks to me the the only really pertinent part to the original poster question was...

"Aircraft Instruments"... "installer establishes that (for the aircraft in which) the instrument installed will comply with the applicable regulations"

That doesn't seem real helpful.

Brian.
 
I know the shop here gets all fired up if they find an attitude indicator in a certified airplane that isn't TSOed.
 
PilotAlan said:
I suspect part of it is whether the instrument is required for the operation (part of VFR minimum, or IFR minimum equipment).
If the instrument is not required, you can probably put in just about anything you want.

G-Meters and Variometers are not required for any operation.
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Wrong. Anything installed in a certificated aircraft needs to meet two requirements:

There has to be approval for the particular installation, that is it has to be in comformance with the type certificate, supplemental type certificate, or with accepted practices that are acceptable to the administrator (depending on how many drinks he's had).

Then the part has to meet the standards for its manufacture. This means there needs to be a TSOA, PMA or other manufacturing authority, etc...

A TSO is neither a necessary nor is it a sufficient condition for most installations in an non-commercial aircraft.
 
Tom-D said:
Explain why the FAA approved the glass dash in a C-182S but won't in a up grade on a 182.
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Probably because the G1000 was added by the manufacturer under the production certificate and is now part of the type design.
Just like some aircraft have LED marker lights and strobes from the factory (put in under the airframe manufacturers authority), but retrofit requires an STC from the LED producer (not the airframe manufacturer).

No different than Piper putting the door handle from a 1964 Ford on a Cherokee, but someone wanting to make a replacement has to go through all the STC hurdles. Or Piper putting a Gates Green Stripe belt on from the factory (with a Piper part number), but buying one from Gates and putting it on later requires a 337.
 
flyingron said:
Wrong. Anything installed in a certificated aircraft needs to meet two requirements:

There has to be approval for the particular installation, that is it has to be in comformance with the type certificate, supplemental type certificate, or with accepted practices that are acceptable to the administrator (depending on how many drinks he's had).

Then the part has to meet the standards for its manufacture. This means there needs to be a TSOA, PMA or other manufacturing authority, etc...

A TSO is neither a necessary nor is it a sufficient condition for most installations in an non-commercial aircraft.
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The FAA Small Airplane Directorate does not seem to agree.
http://www.alphasystemsaoa.com/pdf/AlphaSystemsLetter-Signed_Dec2012-WM.pdf
The Alpha Systems AOA is not PMA, STCd, TSOd, or in any way approved by the FAA. Yet they specifically allow its installation as 'not required' and 'supplemental' to the required equipment, and as a minor alteration not requiring a 337.
 
Certified gyros at 3x-10x the price of non-certified ones from the same manufacturing line and manufacturers are BETTER, don't ya know? Come on.

You guys put your Kool-Aid back in the fridge without drinking it again, didn't you?

It's all about Safety.

:mad2:
 
PilotAlan said:
The FAA Small Airplane Directorate does not seem to agree.
http://www.alphasystemsaoa.com/pdf/AlphaSystemsLetter-Signed_Dec2012-WM.pdf
The Alpha Systems AOA is not PMA, STCd, TSOd, or in any way approved by the FAA. Yet they specifically allow its installation as 'not required' and 'supplemental' to the required equipment, and as a minor alteration not requiring a 337.
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That would appear to be an approval in itself. The administrator must have had a few drinks in him that day. Just because they've made a determination that this unit is acceptable doesn't mean you can go around installing anything just because it's not on your required equipment list.
 
flyingron said:
That would appear to be an approval in itself. The administrator must have had a few drinks in him that day. Just because they've made a determination that this unit is acceptable doesn't mean you can go around installing anything just because it's not on your required equipment list.
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lots of wrong conceptions here. read the AC and you will see this ,

f. Standard Part. Is a part manufactured in complete compliance with an established
U.S. Government or industry-accepted specification, which includes design, manufacturing, and uniform identification requirements. The specification must include all information necessary to produce and conform to the part. The specification must be published so that any party may manufacture the part. Examples include, but are not limited to, National Aerospace Standard (NAS), Air Force/Navy (AN) Aeronautical Standard, Society of Automotive Engineers (SAE), Aerospace Standard (AS), Military Standard (MS), etc.

Aircraft instruments are manufactured to a standard acceptable to the administrator (Aerospace Standard) (AS) they do not need a TSO, FAA-PMA or any other higher authorization. When you remove a Cessna gyro you can replace it a Century Gyro with out any higher authorization because the two Gyros are built to the same standard. As long as the replacement part meets the fit form and function of the Type design, you are good to go.
IOWs if it is a AI built to aviations standards any make will do. Keep in mind that you must meet the requirements of part 91 and the type design for redundancy. You can not remove a vac gyro, and replace it with a electronic one, because you have now lost the requirements of the type design.
 
Tom-D said:
Aircraft instruments are manufactured to a standard acceptable to the administrator (Aerospace Standard) (AS) they do not need a TSO, FAA-PMA or any other higher authorization.
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No, but they do need documentation to show they were manufactured to such a standard. If you look in the Aircraft Spruce or similar catalog, you'll find instruments they specifically note are for use in EXP aircraft only -- because they do not meet that test. In addition, there are environments where TSO'd instruments are required, but not for what most of us are doing.
 
Ron Levy said:
No, but they do need documentation to show they were manufactured to such a standard. If you look in the Aircraft Spruce or similar catalog, you'll find instruments they specifically note are for use in EXP aircraft only -- because they do not meet that test. In addition, there are environments where TSO'd instruments are required, but not for what most of us are doing.
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Come on Ron, How can they be acceptable to the administrator if some body didn't approve them.????

Common sense, goes a long way. The Standard parts rule is what allows us to have after market parts. This is why you are not required to use Grumman tires on your Grumman. Any Tire that meets the type certificate's fit form and function can be used.

Basically any part the manufacturer bought off the shelf, you can too.
 
Ron Levy said:
No, but they do need documentation to show they were manufactured to such a standard.

They don't but you do, when you are replacing parts in your production built aircraft

If you look in the Aircraft Spruce or similar catalog, you'll find instruments they specifically note are for use in EXP aircraft only -- because they do not meet that test. In addition, there are environments where TSO'd instruments are required, but not for what most of us are doing.
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AS&S says that you must contact the manufacturer of the part for usage on your aircraft simply to remove them from the liability loop. but when you do contact the manufacturer you can get the "Aerospace Standard" paper work.
That is exactly how I got authority to use AS&S pot fuel senders in my F-24. rather than trying to find the OEM equipment.
Many of the AS&S suppliers are PMA authorized, and many have the Approval to be direct replacement parts, but do not sell thru AS&S as PMA parts because they can sell cheaper to the EXP operators with out the paper.

thus the statement.
 
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Tom-D said:
Basically any part the manufacturer bought off the shelf, you can too.
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Tom, this is a serious question. If that is the case, why has the FAA required a Field Approval to use a Gates Green Stripe alternator belt, rather than the Piper one (a Gates Green Stripe with the Piper part number written in Sharpie marker)?
That's an issue of much controversy over at the Cherokee Pilots' Association.

Of course there's lots of folks with ~40 year old Piper alternator belts that look brand new. ("The logs say that's the same belt that came from the factory, sir")
 
PilotAlan said:
Tom, this is a serious question. If that is the case, why has the FAA required a Field Approval to use a Gates Green Stripe alternator belt, rather than the Piper one (a Gates Green Stripe with the Piper part number written in Sharpie marker)?
That's an issue of much controversy over at the Cherokee Pilots' Association.

Of course there's lots of folks with ~40 year old Piper alternator belts that look brand new. ("The logs say that's the same belt that came from the factory, sir")
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If Piper had bough the Gates green strip you could too. the Gates may be better but no one at gates has asked for approval, other wise it is not considered Aerospace Standard. (aviation quality)

A modification how ever small is still a modification. Better is a modification.
 
Tom-D said:
If Piper had bough the Gates green strip you could too. the Gates may be better but no one at gates has asked for approval, other wise it is not considered Aerospace Standard. (aviation quality)

A modification how ever small is still a modification. Better is a modification.
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But it appears piper did just buy it off the shelf, same goes for facet fuel pumps, you can buy one for $60 from AS&S or you can pay $600 for the exact same one from piper that has an ink jet piece of paper glued to it that says something about being approved. The one from Piper still has "Facet Automotive Fuel Pump" written right on it.
 
flyingron said:
Wrong. Anything installed in a certificated aircraft needs to meet two requirements:

There has to be approval for the particular installation, that is it has to be in comformance with the type certificate, supplemental type certificate, or with accepted practices that are acceptable to the administrator (depending on how many drinks he's had).

Then the part has to meet the standards for its manufacture. This means there needs to be a TSOA, PMA or other manufacturing authority, etc...

A TSO is neither a necessary nor is it a sufficient condition for most installations in an non-commercial aircraft.
Click to expand...

So where do I find a G-meter that meets these requirements?

Brian
 
bartmc said:
But it appears piper did just buy it off the shelf, same goes for facet fuel pumps, you can buy one for $60 from AS&S or you can pay $600 for the exact same one from piper that has an ink jet piece of paper glued to it that says something about being approved. The one from Piper still has "Facet Automotive Fuel Pump" written right on it.
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When you spend the money to prove these items are Aerospace Standard, every on on the piper forums will love you.

But remember, a lot of this is about the companies wanting the liability of the usage.
 
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