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337 for Vacuum System Removal

Shootingfish

Registered User
Vancouver, WA
Has anyone removed their vacuum system from their PA-12 that has had a vacuum system installed?

I am looking for a 337 paperwork.

I am looking on the TCDS and I am not seeing the vacuum system listed anyplace, is it required equipment on the 12?

The plan is to install 2 AV-30C units and remove the vacuum system.

Thanks in advance.

CW
 
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I think most FSDOs now say you need a 337 off if you needed a 337 on. If it was listed as an option on the type certificate, then on/off is logbook entry.

If not on the type certificate, then it was probably an STC. But then, if you have no "on" 337, who would know if you took it off?
 
Get a copy of the 337's from OK City. You'll want them for review if nothing else.

Look. The big taboo is undocumented maintenance. Just don't EVER do that. I don't care that the feds will come after you for that, in the long run you'd be screwing over every mechanic and IA that has to work on that aircraft, even after you sell it. So. Remove your vacuum system components (All of them. Don't leave unused stuff behind.) Then remove any vacuum driven instruments. Document all of these actions in the airframe log. Finally, update your weight and balance sheet to reflect the removal of these items. Once that's done, the worst that can happen is that you piss of a fed and he tells you that you didn't do a 337 for the removal of those items (not as per regs but feds sometimes want you to do things that aren't in the regs). As long as you documented the removal correctly, all he can really do is try to make you do a new 337. He can't bust you for improper or undocumented maintenance.

Web
 
We would never do undocumented maintenance, we are just looking to the tribe for the knowledge of if we need to do a 337 for the removal of the vacuum system or if it purely a logbook entry for the removal. All of the associated equipment would be removed and then a new W/B completed at that time.

CW
 
Vacuum system was not on the TC, so it’s not “required” equipment. Same with those instruments. Logs are missing, so those MAY have been installed via a 337. Or, maybe installed and logged as a minor.

Get the records as Web says, but remove the system and it’s components and log it. If your mechanic insists it needs a 337, do it, otherwise, just log it and go fly.

At one point, I wanted an artificial horizon in a govt. Cub. Scared myself once too often. Maintenance installed an electric gyro, Merril Field FSDO said it needed a field approval, which they signed off on.

A year later, Alaska Region FAA said you couldn’t install that instrument…seriously, they rescinded the FA. Our Chief of Maintenance at the time called me, and told me to remove the Airworthiness Certificate from that plane and mail it to him. I said, “So, you’re grounding the plane?”

His response was classic: “Nope, you are a government pilot and that’s a government airplane, you don’t need no Airworthiness Certificate.” Turns out, he took the Certificate downtown and gave it to the Regional Administrator of FAA’s Secretary, with a letter similarly worded, and requested she pass it along to her boss.

Never heard another word about it.

MTV
 
I second Web. Remove and document it, and move on. Why does the FSDO even need to be involved? They aren’t in the business of analyzing 70 year old planes for every change and comparing them with 70 year old logbooks. During a ramp check is an ASI going to say “this plane had a vacuum system installed in 1954, show me it was removed with a 337!”?

No one would ever care except a busybody IA that is trying to pad their billable hours with paperwork, and not making airplanes better and more reliable.


Sent from my iPhone using SuperCub.Org
 
No one would ever care except a busybody IA that is trying to pad their billable hours with paperwork, and not making airplanes better and more reliable.
That busybody IA is just covering his rear end in order to keep the license which earns his living.
 
I run 2 AV-30Es, and have for a couple years,,,, The AI has a bug that when the airplane is not level and you start up. The AI will spin and issue AOA warnings. On startup the AV30 will align, if movement happens before the alignment flag stows, or if sitting unleveled, the AI is unreliable. Mine are current with the latest SBs and firmware,, I still like mine and have learned to deal with it. I can reset in level flight and it works fine after. My buddy with the AV30Cs removed his from his Maule because he could not live with it.. Known issue if you research it. Like I said, overall I'm pleased with mine.
 
I too have a pair of AV-30C devices. I’ve experienced what stid2677 noted at startup, but it always erects fine as soon as level. If you move before it aligns, same thing….but no big deal, in the short time it takes to align, you SHOULD be monitoring engine parameters and getting the plane ready to taxi.

More critical in the certified world is DG precession in the instrument set up as a DG. These units really need a remote magnetometer to be reliable, at least in planes with four cylinder engines. Vibration causes precession. uAvionix has a remote magnetometer approved for the Experimental installs, but not for the Certified, yet. Working on it.

I removed my vacuum system, as well as the failed DG and the AH that was headed south, installed two AV-30C and am very pleased with them. I look forward to them getting the remote magnetometer approved for certified, but not in a big panic. I have an O-360, and even with a MT prop, balanced, those engines shake.

If I were flying a Cub, I’d definitely install ONE AV-30C, set up as an attitude instrument. My GPS and whiskey compass could serve as he “DG”….and looking it the front.

BUT, to me the HUGE benefit to the AV-30 is that it can display all kinds of very useful data, besides attitude. Like direct readout Density Altitude, true airspeed, G limits, AOA, etc, etc. And, BTW, if you install only one AV-30, it can display BOTH attitude and direction.

They are great units, and seriously, I wish I’d had ONE of these things back when I spent a lot of time churning around at 200 agl.

MTV
 
If there was a 337 to install the vacuum system then a 337 simply stating the vacuum system was removed returning the aircraft to the original configuration. W&W and equipment list has been updated. Is all you need. The approved data is the original type design.

If no 337 was used to install it, a log book entry is all that is required to remove it as it is a minor alteration. Read AC 43-210a and use the flow chart. Don’t make it more complicated than it is.

Oh, yeah, it is the A&P that makes the Major/Minor determination, not the FAA. Use the guidance FAA provides to your advantage. If FAA questions it, throw it back in their face with supporting documentation!


Sent from my iPad using Tapatalk
 
I second Web. Remove and document it, and move on. Why does the FSDO even need to be involved? They aren’t in the business of analyzing 70 year old planes for every change and comparing them with 70 year old logbooks. During a ramp check is an ASI going to say “this plane had a vacuum system installed in 1954, show me it was removed with a 337!”?

No one would ever care except a busybody IA that is trying to pad their billable hours with paperwork, and not making airplanes better and more reliable.


Sent from my iPhone using SuperCub.Org

Removing and installing systems is not preventive maintenance. If you do it it must be under the supervision of an A&P.


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No one would ever care except a busybody IA that is trying to pad their billable hours with paperwork, and not making airplanes better and more reliable.
I have plenty of billable work that I don't want to do un-needed paperwork just to bill a customer. I will do the paperwork I see as required in the regs to make sure my tickets are not compromised.
 
At the end of my last Annual the IA requested I review all my prior paperwork, as well as his recently completed squawk list and logbook entries. He wanted me to fulfill my responsibility for maintaining airworthiness. So I did to the best of my ability. I had the FAA's records going back to 1941 plus logs. That was the first time an IA made that request and I appreciated that attention to detail.

Gary
 
I keep lists of all ADs and major alterations in the back of each aircraft’s current logbook. I probably should keep a list of major repairs as well.
 
I have plenty of billable work that I don't want to do un-needed paperwork just to bill a customer. I will do the paperwork I see as required in the regs to make sure my tickets are not compromised.

At no time did I mention you. I would fully trust you do a great job based on your reputation here and after watching your videos. I have heard many other horror stories though, both here, and in person, about an IA that had ridiculous squawks that seemingly only added billable hours. I have also heard of a $100 per 337 fee.


Sent from my iPhone using SuperCub.Org mobile app
 
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FSDO's have quick access directly to FAA records. They would know if there was a 337 previously filed. Whether they would share that info and offer an opinion regarding needed paperwork is another matter to be explored.

At one time I had an IA that would do an inspection and generate a squawk list. He would then have me address the list with the help of an A&P or two. They would agree on a result and an A&P would return the airplane to service. I think that's what happened.

See: https://www.faa.gov/training_testing/testing/media/ia_info_guide.pdf

Gary
 
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At no time did I mention you. I would fully trust you do a great job based on your reputation here and after watching your videos. I have heard many other horror stories though, both here, and in person, about an IA that had ridiculous squawks that seemingly only added billable hours. I have also heard of a $100 per 337 fee.


Sent from my iPhone using SuperCub.Org mobile app

I hate to think there are mechanics like that but I know there are.
 
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