Rebuilding certified T&F as EAB

[Ed Haywood]

Would it be possible to rebuild a certified tube and fabric aircraft such as a champ or citabria as EAB?

I searched POA and found several discussions saying it would be next to impossible for a Cessna 172 or similar aluminum monocoque aircraft. I assume that is due to the impracticality of reaching the 51% threshold with that kind of construction.

But with a T&F aircraft, disassembly to bare frame is a regular lifecycle event, and having to cut out and weld frame members is not unusual.

I am wrapping up that process with a Decathlon, and am confident I built more that 51% of the aircraft. I am working under supervision and so will remain certified. But it got me thinking about viability of restoration projects for those without access to someone willing to supervise.

 

[Initial Fix]

You can do experimental with either the t&f or your 172 example. But, it wasn’t clear (just implied) in you first post if you are wanting to also do the maintenance like you could with a 51% build. Otherwise A&P just does the maintenance.

 

[DaleB]

EAB? No. There are other Experimental carts you might be able to use, like Exhibition or something, but no. You’re repairing a TC airframe, not building new. I seem to recall there’s an FAA letter out there about reusing major components of airplanes for EAB. I know it was possible to do stuff like that in the past, but that went away in rhe 70s or 80s, I think.

 

[Capt. Geoffrey Thorpe]

Using / rebuilding existing parts does not count towards your 51% no matter how much work you do on them. The FAA considers that "repair" not fabrication. They make that point several times in AC20-27G https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_20-27G.pdf

"You will not receive credit for work done on, or the use of, salvaged major
assemblies or subassemblies when determining whether your amateur-built aircraft has
met the major portion requirement. This would include any “rebuilding” or “alteration”
activities to return these components to an airworthy condition"

"Converting a Type-Certificated Aircraft to an Amateur-Built Aircraft. The
practice of performing alterations, repairs, and rebuilding of previously type-certificated
aircraft for the purpose of obtaining an experimental amateur-built airworthiness
certificate is not authorized under § 21.191(g). Such maintenance actions properly fall
under 14 CFR part 43, Maintenance, Preventive Maintenance, Rebuilding, and
Alteration. You will not receive credit for these actions toward fabrication or assembly.
We will not accept applications for airworthiness inspections on such aircraft."

 

[Ed Haywood]

Using / rebuilding existing parts does not count towards your 51% no matter how much work you do on them. The FAA considers that "repair" not fabrication. They make that point several times in AC20-27G https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_20-27G.pdf

"You will not receive credit for work done on, or the use of, salvaged major
assemblies or subassemblies when determining whether your amateur-built aircraft has
met the major portion requirement. This would include any “rebuilding” or “alteration”
activities to return these components to an airworthy condition"

"Converting a Type-Certificated Aircraft to an Amateur-Built Aircraft. The
practice of performing alterations, repairs, and rebuilding of previously type-certificated
aircraft for the purpose of obtaining an experimental amateur-built airworthiness
certificate is not authorized under § 21.191(g). Such maintenance actions properly fall
under 14 CFR part 43, Maintenance, Preventive Maintenance, Rebuilding, and
Alteration. You will not receive credit for these actions toward fabrication or assembly.
We will not accept applications for airworthiness inspections on such aircraft."

Seems pretty cut and dried. Thanks.

Typical bureaucratic thinking. AFAIK the FAA has no problem with purchasing a steel frame fabricated by a kit builder or component vendor for use in EAB. What is the logic in ruling out a frame just because it was originally made in a factory on a proper jig? Certainly not safety.

Too bad. There are plenty of derelict vintage aircraft out there which could be revived this way.

 

[Capt. Geoffrey Thorpe]

AFAIK the FAA has no problem with purchasing a steel frame fabricated by a kit builder or component vendor for use in EAB. What is the logic in ruling out a frame just because it was originally made in a factory on a proper jig?

In both of those cases, the fabrication of the fuselage would not count towards your 51%. From the kit builder, you may get some credit for the assembly of some parts into the airplane that you wouldn't otherwise get, but overall not a HUGE difference if it's just that one component. But if you take the whole Decathalon - wings, tailfeathers, fueslage, wing ribs, wing spars, landing gear, control stick, fuel tanks, etc. etc. etc. rebuilt and/or repaired (like I assume you did), U B Skrewt.

I would point out that the so called 51% rule has nothing to do with 51% of the time or effort to construct an aircraft - it's all about scoring above 51% on the checklist found in appendix 8 in the link above. In that list, fabricating a control stick or calibrating the fuel system counts as much as cutting out, drilling, and dimpling the fuselage skin from flat stock.

 

[unsafervguy]

Seems pretty cut and dried. Thanks.

Typical bureaucratic thinking. AFAIK the FAA has no problem with purchasing a steel frame fabricated by a kit builder or component vendor for use in EAB. What is the logic in ruling out a frame just because it was originally made in a factory on a proper jig? Certainly not safety.

Too bad. There are plenty of derelict vintage aircraft out there which could be revived this way.

the difference i that the FAA looks at the any part that came off a previously built aircraft as a repair, not fabrication. the problem is a few people were abusing the rules so the FAA shut it down.

 

[Racerx]

@rwellner98 has an experimental maule. But i don't think it'd be considered EAB or qualify for a repairman's cert.

Experimental Maule? - KITPLANES

One of the inherent pleasures of OSH are the little gems, rarities, and curiosities that one can stumble upon. One of those present this year is an apparent “Maule” parked in homebuilt camping like an Asian bike at Sturgis. Closer inspection shows that the airplane is no carpetbagger as it has...

www.kitplanes.com

 

[Stewartb]

Not cut and dried at all. The only ones who think it is most likely haven’t built a kit plane under E-AB. You can’t take credit for building parts you didn’t build, but that’s not a big deal. The E-AB points list still provides you lots of opportunities to score points. With that you use their formula to calculate 51%. In my own kit? Airframe, wings, control surfaces, landing gear, etc. arrived completely assembled. I employed commercial assistance (also allowed and accounted for on the tally sheet) and easily surpassed 51%. Furthermore, when the DAR comes to do the inspection and issue the AW Cert will be the first time he sees the airplane. He may ask for build photos or a builder log, but he may not. Given what you’re suggesting? You probably need to assemble a parts list for your build, a “kit” catalog of sorts, and talk to a DAR. You’ll learn that not all DARs approach the process the same. You need to be careful not to represent the project as a reassembly of a certificated airplane. That’s not allowed, but assembling a stack of parts and making an E-AB is allowed. Download the tally sheet and the formula to figure your points and use it to see if you make the minimum.

 

[GeorgeC]

What's the deal with a plane like the Breezy, where the wings come off a TC'd airplane?

 

[tsts4]

What's the deal with a plane like the Breezy, where the wings come off a TC'd airplane?

It’s not that you can’t use already fabricated parts, it’s just when you run the checklist the total can’t exceed 49%. My guess is the Breezy squeaks by, or did at the time as I don’t know when someone last built one.

 

[Stewartb]

The 51% build score is compiled from using the attached list and adjusting using the FAA’s formula at the end of it. Notice there are fabrication points for parts. When using a pre-fab part the builder can’t get points in that column. That’s true whether using certificated parts or an experimental kit part. Not a deal breaker. The two columns on the right are for the builder. Some areas are grayed out. The ones that aren’t are available to take up to one point. The sum of columns across can’t exceed 1, so pro assistance may get .5 and the builder .5. That’s perfectly legal. Not all lines get points. Populate the list, add up the columns, and adjust per formula. If you get 51% per the formula and are willing to sign the affadavit stating so? You should qualify.

https://www.faa.gov/aircraft/gen_av/ultralights/amateur_built/kits/media/AmBuiltFabAssyCklistFW.pdf

 

[rwellner98]

@rwellner98 has an experimental maule. But i don't think it'd be considered EAB or qualify for a repairman's cert.

Experimental Maule? - KITPLANES

One of the inherent pleasures of OSH are the little gems, rarities, and curiosities that one can stumble upon. One of those present this year is an apparent “Maule” parked in homebuilt camping like an Asian bike at Sturgis. Closer inspection shows that the airplane is no carpetbagger as it has...

www.kitplanes.com

I mean, you linked an article that pointed out that it's EAB.

 

[pfarber]

In both of those cases, the fabrication of the fuselage would not count towards your 51%. From the kit builder, you may get some credit for the assembly of some parts into the airplane that you wouldn't otherwise get, but overall not a HUGE difference if it's just that one component. But if you take the whole Decathalon - wings, tailfeathers, fueslage, wing ribs, wing spars, landing gear, control stick, fuel tanks, etc. etc. etc. rebuilt and/or repaired (like I assume you did), U B Skrewt.

I would point out that the so called 51% rule has nothing to do with 51% of the time or effort to construct an aircraft - it's all about scoring above 51% on the checklist found in appendix 8 in the link above. In that list, fabricating a control stick or calibrating the fuel system counts as much as cutting out, drilling, and dimpling the fuselage skin from flat stock.

you must read and understand what the FAA regards as credit for building a part. if you buy a spar, but its not cut to size or is missing a few holes, and then you cut it to size or add those holes you get full and complete credit for fabrication of the spar. So you are actually doing far less than 51% of the work.