Converting Certified to Experimental

[ArrowFlyer86]

I'm curious, is there a pathway, even a challenging/rare one that allows you to convert your certified piston aircraft to an experimental one?
For instance, let's say you had plans to make modifications in the name of testing new technologies/equipment onboard. Are you able to do that?

If not, then a separate question is what regulations allow manufacturers to test engines/avionics/<literally any modifications> on existing certified aircraft before an STC is established for them?

 

[wanttaja]

If you have a legitimate reason, you can get approval to place the aircraft in the Experimental Research and Development category, Experimental Market Survey category, etc.

If you have a good story, you can get approval to place the aircraft in the Experimental Exhibition category.

None of the categories give you the freedom that Experimental Amateur-Built does. A major difference is that the other Experimental categories are only valid for a year. However, Experimental Exhibition comes close, as far as minimal impact.

Ron Wanttaja

 

[wanttaja]

If not, then a separate question is what regulations allow manufacturers to test engines/avionics/<literally any modifications> on existing certified aircraft before an STC is established for them?

Here's a diagram showing all the certification categories in the US:

You can see the nine categories under "Experimental"; obviously, manufacturers or commercial modifiers can take advantage of the Experimental Show Compliance with Regulations or Experimental R&D ones.

Ron Wanttaja

 

[aterry1067]

Here's a diagram showing all the certification categories in the US:
View attachment 130049
You can see the nine categories under "Experimental"; obviously, manufacturers or commercial modifiers can take advantage of the Experimental Show Compliance with Regulations or Experimental R&D ones.

Ron Wanttaja

Interesting. Thanks! I didn’t realize there was a distinguished regulatory difference between “Amateur Built” and “Kit Built”. I would think the line is also a little fuzzy between “Show Compliance” and “R&D”.

Do you have a link for this chart, or where I could find more info?


Edit: never mind on the link. I just noticed the CFR title at the top.

 

[aterry1067]

Legal definitions:

 

[tsts4]

Interesting. Thanks! I didn’t realize there was a distinguished regulatory difference between “Amateur Built” and “Kit Built”. I would think the line is also a little fuzzy between “Show Compliance” and “R&D”.

It is not the kits normally associated with E-AB aircraft. The "Kit-Built" category in this instance is in relation to "Primary Category" certified aircraft with a production certificate. If a Primary Category kit is built without the production certificate holder's supervision then it can only be certified under that specific Experiential category.

 

[wanttaja]

Interesting. Thanks! I didn’t realize there was a distinguished regulatory difference between “Amateur Built” and “Kit Built”.

You found the listing in Part 21 that includes the definition of each, but the "Kit Built" category is not the usual "homebuilt kit." At one point, manufacturers such as Piper produced "Kit" versions of their products, which could be assembled by customers but had a lot more stringent checking to ensure they met the same standards as the production version of the airplane.

Ron Wanttaja

 

[ArrowFlyer86]

If you have a legitimate reason, you can get approval to place the aircraft in the Experimental Research and Development category, Experimental Market Survey category, etc.

If you have a good story, you can get approval to place the aircraft in the Experimental Exhibition category.

None of the categories give you the freedom that Experimental Amateur-Built does. A major difference is that the other Experimental categories are only valid for a year. However, Experimental Exhibition comes close, as far as minimal impact.

Ron Wanttaja

Ahh that's the key: you can only get the certification for a year.
So you wouldn't bother making a permanent change to your aircraft then, right? Because if you did, then in a year you'd lose your experimental category and have to revert back?
I'm thinking about cases like this guy (granted he did it with an experimental aircraft). If you did that with a certified aircraft you'd either have to finish testing and get an STC to keep it, or revert back to normal certified standards a year later?

 

[aterry1067]

You found the listing in Part 21 that includes the definition of each, but the "Kit Built" category is not the usual "homebuilt kit." At one point, manufacturers such as Piper produced "Kit" versions of their products, which could be assembled by customers but had a lot more stringent checking to ensure they met the same standards as the production version of the airplane.

Ron Wanttaja

Well thanks! TIL

I can now call my day complete.

 

[Bell206]

So you wouldn't bother making a permanent change to your aircraft then, right? Because if you did, then in a year you'd lose your experimental category and have to revert back?

Depends on whether your alteration requires a permanent change to the aircraft. But that is done also. The annual limit only requires you to resubmit your application every year. I know of a number of aircraft that are "permanently" Experimental-Exhibition and renew their certificate each year. There are a number of guidance docs on this.

But each category has its own limits/restrictions but none prevent you from converting back to your original standard AWC provided it conforms to its TC and is safe for flight.

In the real world, the movement between standard AWC to special AWC happens on a regular basis in some circles.

 

[DaleB]

Talk to the guy with the LS V8-powered Cessna.

https://corsairpower.com/converting-standard-aircraft-to-experimental/

Their site loads ridiculously slowly.

 

[nauga]

I would think the line is also a little fuzzy between “Show Compliance” and “R&D”.

In reality there is a hay-uge difference between the two. Compliance requires a standard to comply with, like 14 CFR Part 23. You may have an airplane you're preparing for type certification and you want to show that your 'conforming' design complies with some aspect of that standard. The data from those test can be used as part of your TC application assuming you can demonstrate conformity (matches the design to be submitted for TC) in addition to compliance (meets the standard). For R&D, all bets are of. There does not need to be a standard, there does not need to be a design, there does not even need to be an existing aircraft category or class. Powered lift, E/VTOL, and passenger carrying autonomous aircraft are examples of these. With standards for some either in the works or a loooooong way off it's up to the R&D organization to figure out what to do and how to do it, and what you see may not bear any resemblance to anything that subsequently receives a TC.

Nauga,
who was wondering
which side of the fence he was on. (with apologies to Adam Ant)

 

[hindsight2020]

just go EAB now. Trust me bro.

 

[ArrowFlyer86]

just go EAB now. Trust me bro.

Haha - you can see exactly what loophole I was angling for.

 

[hindsight2020]

Haha - you can see exactly what loophole I was angling for.

It's just I was asking the exact same questions on here and offline circa 12 years ago. Answer never changed. And that was in a very favorable, disinflationary decade in username checks fashion. BL, I'm just trying to save you the belabored evolution.

 

[AvNavCom]

I have long thought that a pathway from certified to a category similar to EAB would be an elegant way to keep some of the older aircraft flying. The exact numbers would take some debating, but I envision any aircraft older than 50 years or any aircraft with a manufacturer that is out of business more than 10 years could have a one-time, one-way conversion to the Experimental category at the request of the owner. After the conversion, the aircraft could never be used for commercial operations but would gain the freedom to use replacement parts and avionics similar to EAB aircraft today and wouldn't have any of the additional baggage required for exhibition and so forth. Especially with MOSAIC arriving in the near future, the requirements for Certified light aircraft vs. (frequently higher performance) EAB light aircraft really don't make much sense to me.

 

[ArrowFlyer86]

I have long thought that a pathway from certified to a category similar to EAB would be an elegant way to keep some of the older aircraft flying. The exact numbers would take some debating, but I envision any aircraft older than 50 years or any aircraft with a manufacturer that is out of business more than 10 years could have a one-time, one-way conversion to the Experimental category at the request of the owner. After the conversion, the aircraft could never be used for commercial operations but would gain the freedom to use replacement parts and avionics similar to EAB aircraft today and wouldn't have any of the additional baggage required for exhibition and so forth. Especially with MOSAIC arriving in the near future, the requirements for Certified light aircraft vs. (frequently higher performance) EAB light aircraft really don't make much sense to me.

Same!

From the link that DaleB posted it sounds like there is maybe something along those lines in Canada?
Not sure how authoritative the CorsairPower source is on regs, though

 

[flyingron]

Interesting. Thanks! I didn’t realize there was a distinguished regulatory difference between “Amateur Built” and “Kit Built”. I would think the line is also a little fuzzy between “Show Compliance” and “R&D”.

Do you have a link for this chart, or where I could find more info?


Edit: never mind on the link. I just noticed the CFR title at the top.

Kit-built is a LSA subgrouping. If you build a kit that doesn't fit into that definition, it gets to Experimental Amateur built.

R&D and show compliance are someone equivalen. Show compliance is typically for just test flying after some non-certificated change is made to get it approved. R&D is for ongoing product development.

 

[flyingron]

Canada has an owner-maintenance category but it's not eligible for all certificated designs. Note that it's a "one-way street." There's no way to go back after you put an airplane in that category.

The FAA has opened up a new program called VARMA. If your plane is older than 1980, there is an eased way to get parts approved. It's kind of an extension of what was called the "owner-produced" part policy that was in place before... https://www.faa.gov/regulations_pol...fm/go/document.information/documentid/1021446

 

[AvNavCom]

The problem with VARMA, as I understand it, is that it requires a mechanic to put their signature in a logbook saying that a fabricated part is airworthy. GA mechanics in general are already really worried about liability since they became juicier targets for litigation after GARA limited manufacturer liability. Talking to local guys around here, they won't touch VARMA because they are worried that some distraught spouse will decide that the non-standard part they signed off was the cause of the accident. To get to a solution, I think we need something which allows mechanics to sign off that something was installed in accordance with standards and practices, but without the need to take on liability for the part itself.

 

[Racerx]

@rwellner98 has an experimental Maule

 

[Bell206]

Especially with MOSAIC arriving in the near future, the requirements for Certified light aircraft vs. (frequently higher performance) EAB light aircraft really don't make much sense to me.

Several years ago there was a push by the EAA and others to create a Primary Non-Commercial category of aircraft. It was similar to the TCCA Owner Maintained mentioned above but had several major differences. Unfortunately, the main players tried to piggyback PNC onto the rewrite of Part 23 which was the wrong venue and it was dropped to complete the rewrite. Why EAA, AOPA, etc haven't tried to resurrect that movement no clue.

However, I believe something is being proposed/discussed within the MOSAIC NPRM concerning the maintenance side. The fact they want to change the certification standards for an LSA repairman to the same ones used for an A&P makes myself and others think this may be to expand on the type of aircraft that can be worked. The main problem with the Canadian owner mx program is that those aircraft no longer conform to ICAO and other international agreements so those aircraft can never leave Canada. Using the same A&P standards for LSA mx may just be some sort compromise for TC aircraft that fall under LSA limits to be worked on by individuals with a LSAM cert but below an A&P cert....?

The problem with VARMA, as I understand it, is that it requires a mechanic to put their signature in a logbook saying that a fabricated part is airworthy.

Mechanics can't produce parts in that fashion. They can only fabricate certain parts when consumed in a repair or alteration per Part 21. VARMA is supposedly a new part approval process that fits in between TC, PMA, TSO parts and owner-produced parts. However, the only references I've seen are from EAA who the main instigator of the process. Without anything official from the FAA on how to use the process its tough to add more. But if VARMA does expand it would be a huge change on replacing parts on older aircraft and streamline the existing methods of part replacements.

However, a mechanic still owns the liability on any part they install that it conforms to its approved data and is airworthy regardless how that part produced or manufactured. No free lunch.

 

[AvNavCom]

Mechanics can't produce parts in that fashion. They can only fabricate certain parts when consumed in a repair or alteration per Part 21. VARMA is supposedly a new part approval process that fits in between TC, PMA, TSO parts and owner-produced parts. However, the only references I've seen are from EAA who the main instigator of the process. Without anything official from the FAA on how to use the process its tough to add more. But if VARMA does expand it would be a huge change on replacing parts on older aircraft and streamline the existing methods of part replacements.

Thanks for the clarification! I guess it's more for off-the-shelf, "low-risk" parts which need mechanic validation that they are suitable for use.

Personally, I would love for there to be some sort of repairman certificate which would allow me to do work on my own Cherokee without the requirement to meet the comprehensive skill-set and knowledge needed for an A&P. I try to do all of the allowable maintenance on my aircraft, along with whatever my long-suffering A&P is willing to teach me (e.g. rebuilding struts) under his supervision. I have definitely come to better understand my aircraft by doing an owner-assisted (or owner-impaired, perhaps) annual inspection, and I think it has made me a better pilot in some respects!

 

[hindsight2020]

Personally, I would love for there to be some sort of repairman certificate which would allow me to do work on my own Cherokee without the requirement to meet the comprehensive skill-set and knowledge needed for an A&P.

yabut the "guild" is antagonized by your desire (especially when publicly expressed) to seek independence via regulatory relief. They complain about liability and your small fry work not being worth their time on one side of their mouth, then screech to hell out the other when you go ask the regulator for "release on own recognizance". If their license required a medical they'd all be SI-deferred for bipolar disorder

 

[Tokirbymd]

Thanks for the clarification! I guess it's more for off-the-shelf, "low-risk" parts which need mechanic validation that they are suitable for use.

Personally, I would love for there to be some sort of repairman certificate which would allow me to do work on my own Cherokee without the requirement to meet the comprehensive skill-set and knowledge needed for an A&P. I try to do all of the allowable maintenance on my aircraft, along with whatever my long-suffering A&P is willing to teach me (e.g. rebuilding struts) under his supervision. I have definitely come to better understand my aircraft by doing an owner-assisted (or owner-impaired, perhaps) annual inspection, and I think it has made me a better pilot in some respects!

I think one issue with this is what happens after you sell the plane? Lets say you have a limited A&P type certificate and you replace/repair a control cable. Then you sell the plane. The next owner is now saddled with potentially "sub-par" work (or at least work not performed by a fully certified A&P). I am in support of more limited A&P programs- I would love to get mine but I don't have 2y to devote away from my current career, and the turbine work etc would never be in my wheelhouse. I'm happy to have a great relationship with my mechanic and as you mention, do as much as I can under his tutelage/supervision. But not everyone has this availability, and with the decline in number of active GA A&Ps is only going to get worse.

 

[Bell206]

I try to do all of the allowable maintenance on my aircraft, along with whatever my long-suffering A&P is willing to teach me (e.g. rebuilding struts) under his supervision.

Good on you. But you don’t have to stop there. There are a number of free guidance documents out there that can teach you the basics on all things maintenance related on your aircraft.

Perhaps if you educate yourself on more systems and tasks, your mechanic might let you expand the work he allows under supervision? For example, I had some owner-assist customers who changed engines under supervision as they took the time to learn the basics for the job.

The next owner is now saddled with potentially "sub-par" work (or at least work not performed by a fully certified A&P).

In my opinion, a limited-A&P program will not degrade the work performed. The certificate doesn’t make the person. Plus any formal limited A&P program will have performance standards to meet just as a regular A&P.

In my experience, the potential for “sub-par” work is more evident from owners who think the current system is a scam or identify as hangar fairies and perform work with no documentation. Some owners will even gladly accept this “sub-par” level of work especially if it saves them a buck or two like a 20 minute annual sign-off. Unfortunately, there are some APIAs who are happy to accommodate them for an easy buck.

Regardless, I believe most mechanics would support an A&P-Lite program as it would put those willing to participate on the same level performance-wise. But, no matter how they tweak the system, all maintenance starts with the owner and ends with the owner regardless how that owner thinks the system should work.

 

[pfarber]

but without the need to take on liability for the part itself.

authority without responsibility is a path to MX just signing anything to get paid. If there is no fear of liability then there what forces an MX to do any amount of work to validate and verify the part is made correctly?

 

[pfarber]

Good on you. But you don’t have to stop there. There are a number of free guidance documents out there that can teach you the basics on all things maintenance related on your aircraft.

Perhaps if you educate yourself on more systems and tasks, your mechanic might let you expand the work he allows under supervision? For example, I had some owner-assist customers who changed engines under supervision as they took the time to learn the basics for the job.

In my opinion, a limited-A&P program will not degrade the work performed. The certificate doesn’t make the person. Plus any formal limited A&P program will have performance standards to meet just as a regular A&P.

In my experience, the potential for “sub-par” work is more evident from owners who think the current system is a scam or identify as hangar fairies and perform work with no documentation. Some owners will even gladly accept this “sub-par” level of work especially if it saves them a buck or two like a 20 minute annual sign-off. Unfortunately, there are some APIAs who are happy to accommodate them for an easy buck.

Regardless, I believe most mechanics would support an A&P-Lite program as it would put those willing to participate on the same level performance-wise. But, no matter how they tweak the system, all maintenance starts with the owner and ends with the owner regardless how that owner thinks the system should work.

as long as my signature is not on it why do I care? My certificate does not require me to be the safety police.
Would I want to touch a repair that an MX-lite did before me? NOPE. Because now all the liability comes to me. And that's if we can trust the logbooks. lol sure.

Preventative MX allows for a ton of things that owners are not doing now. Things not on the PM list a generally things that require extra tools and training. As an MX I am not legally allowed to perform any work that I have not done before under supervision.... yet you want owners to just plow ahead without even that?

 

[Pinecone]

The way I would see an A&P Lite would be the same standards as a regular A&P, but limited in areas that the Lite version could do.

A piston single Lite would not need anything turbine. Could also differentiate between all metal and composite and tube/fabric and wood structures for work.

 

[moparrob66]

I would argue that an owner should be able to completely switch from certified to owner-maintained, with the understanding that it could never go back. You wouldnt want to buy a certified airplane that was experimental for a while but switched back to certified with no idea who did what to it, with parts from Auto Zone.

Well, maybe if the price was right....

 

[Bell206]

The way I would see an A&P Lite would be the same standards as a regular A&P, but limited in areas that the Lite version could do.

FWIW: I think the “A&P-Lite” might actually be a misnomer and we should call it a LS-AMT certificate. As I mentioned above on MOSAIC, with the increase in aircraft types that could fall under LSA, perhaps they are looking at a mechanics certificate to maintain those collective LSA aircraft regardless if they are TC’s or ASTM’d?

And if the LS-AMT uses the same certificate standards as an A&P (MOSAIC NPRM) it would check a lot of boxes that could keep those aircraft in compliance with existing rules which would be different than the TCCA owner mx aircraft.

Would I want to touch a repair that an MX-lite did before me? NOPE. Because now all the liability comes to me.

How does the liability come to you if another “certified” individual performs and signs the work in the record? What would be the difference from an A&P signing off previous work?

 

[AvNavCom]

Good on you. But you don’t have to stop there. There are a number of free guidance documents out there that can teach you the basics on all things maintenance related on your aircraft.

Perhaps if you educate yourself on more systems and tasks, your mechanic might let you expand the work he allows under supervision? For example, I had some owner-assist customers who changed engines under supervision as they took the time to learn the basics for the job.

I appreciate that! I definitely have AC43.13, the aircraft service manual, and the parts manual available whenever I'm planning to commit an act of maintenance. I'll be moving to a new area of the country in the near future, but if I can establish a circle of trust with another A&P in the area, hopefully I can get some more experience. Probably I need to start an actual log-book of the stuff I'm doing. Not sure that I'll ever get an A&P, but you never know.

authority without responsibility is a path to MX just signing anything to get paid. If there is no fear of liability then there what forces an MX to do any amount of work to validate and verify the part is made correctly?

I guess that's why it would be limited to non-critical parts. A door handle can probably be held to the "reasonable person" standard of examining it and seeing if its reasonably fit for purpose. If an OEM or PMA part isn't available for an antique/classic aircraft and the owner is willing to accept responsibility for the installation of an off-the-shelf part from Autozone for a non-critical item, there should be a way for the mechanic to install that without incurring liability themselves as long as it's something manufactured and commercially available. I see your point, and I don't think anyone is arguing for lower standards, but rather that we're rapidly reaching a point where certain parts are becoming ridiculously expensive, if they're available at all. Heck, I just paid $20+ dollars for about five cents worth of plastic to replace a cabin light cover in my Cherokee, just because it's PMA!

 

[Tom J]

I'll be moving to a new area of the country in the near future, but if I can establish a circle of trust with another A&P in the area, hopefully I can get some more experience. Probably I need to start an actual log-book of the stuff I'm doing. Not sure that I'll ever get an A&P, but you never know.

You mention a Navy PCS to Virginia in the near future. Where about? I work in a shop in Tappahannock (XSA) and we are willing to work with owners on assist maintenance. I'm happy to help a fellow Squid stay safely in the air. Reach out when you get to this coast.

 

[Bell206]

I definitely have AC43.13, the aircraft service manual, and the parts manual available whenever I'm planning to commit an act of maintenance.

FYI: there are additional maintenance references that take you down the rabbit hole of the theory and fundamentals of aircraft maintenance. These are the same references a person uses to obtain their A&P. Its some dry, technical stuff but if you combine them with your other books and apply them to the work you perform it brings things togather so to speak.

I'll be moving to a new area of the country in the near future, but if I can establish a circle of trust with another A&P in the area, hopefully I can get some more experience. Probably I need to start an actual log-book of the stuff I'm doing.

I work in a shop in Tappahannock (XSA) and we are willing to work with owners on assist maintenance.

If your plans are to move and if your intent is to find another owner-assist mechanic, perhaps contact an FAA maintenance ASI at the FSDO near your future location and see what they want to see for a "logbook" of maintenance experience to apply toward obtaining your A&P test Form 8160-2. Then see if your current mechanic will help you build that experience record (logbook) to take with you. Then you can have your new mechanic add to that record until you meet the minimums to take the A&P tests.

 

[AvNavCom]

You mention a Navy PCS to Virginia in the near future. Where about? I work in a shop in Tappahannock (XSA) and we are willing to work with owners on assist maintenance. I'm happy to help a fellow Squid stay safely in the air. Reach out when you get to this coast.

That's awesome! I'll be working in the heart of darkness in Falls Church, but I just bought a place in Manassas. I'm planning to keep my plane at HEF for the convenience (just three short years to get a hangar!) but also considered HWY so I don't have to screw around with the emotional coping mechanism surrounding D.C. every time I want to go fly around. I'll definitely reach out once I get there!

If your plans are to move and if your intent is to find another owner-assist mechanic, perhaps contact an FAA maintenance ASI at the FSDO near your future location and see what they want to see for a "logbook" of maintenance experience to apply toward obtaining your A&P test Form 8160-2. Then see if your current mechanic will help you build that experience record (logbook) to take with you. Then you can have your new mechanic add to that record until you meet the minimums to take the A&P tests.

That's a great point. I'll make those calls and see if I can get something started. Certainly wouldn't hurt to have it. Thanks for the advice!

 

[455 Bravo Uniform]

@Bell206 is another POA treasure.

 

[tsts4]

Kit-built is a LSA subgrouping. If you build a kit that doesn't fit into that definition, it gets to Experimental Amateur built.

Not exactly as E-AB isn't a catch all. Yes "Kit-Built" is an Experimental Light Sport sub-category, however the question in post 4 was not related to that. It was related to "Kit-Built Aircraft" as one of the 9 main special airworthiness categories - see posts 3, 5, and 6.

 

[Tokirbymd]

I have been dreaming of a Rotax powered twin- is there a regulatory pathway to take say a twinkie fuslage, taper wings maybe from a Seneca or Saratoga, slap some Rotax 916s on there, maybe faired fixed gear and call it experimental?

 

[moparrob66]

There may be some way to do it without creating what the revenuers would label an illegally modified, certified aircraft, but you're better off using as many kitplane parts as possible. As I understand it, using too many certified parts might run afoul of the 51% rule.

Saw a guy who made a twin using a Vans RV as a starting point. Go for it, but be sure to post pics!

 

[Checkout_my_Six]

We've got a green horn on the line.....