Experimental using part 23 hull as starting point

NordicDave

NordicDave

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A gentleman in Brazil made an experimental Cessna 180 call it an Anssec 180.

Unfortunately it crashed: https://aviation-safety.net/wikibase/279998


Actually this spawns an interesting question regarding USA experimental aircraft.

Keeping the 51% rule in focus. Why couldn't a guy take a quality stripped Cessna airframe with complete empennage and no wings; and then build the wings, windows, interior, avionics, and control cables, etc for the remaining 51%?

Different permutations are possible like completed wings and fuselage, but tail section built from discrete parts.

A Van's quick build kit has the airframe aluminum complete except the empennage.
 
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In theory, you can. There's a checklist of building tasks and you have to check enough of the boxes to qualify for the 51%. But while used parts from other planes are allowed, it can be a stretch if you use major components like a complete fuselage and tail. You'd probably have to completely scratchbuild the wings, used wings from another plane wouldn't do it. The reverse is more common; used wings from another plane and everything else new.
 
NordicDave said:
windows, interior, avionics, and control cables,
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Interior and avionics specifically don't count towards your score.

NordicDave said:
control cables, etc
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One would have to ask if those qualify as new fabrication or simply repair to your existing fuselage.

https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_20-27G.pdf

"d. Use of Salvaged Assemblies from Type-Certificated Aircraft. The use of
used or salvaged assemblies (for example, landing gear, horizontal stabilizer, and
engine mount) from type-certificated aircraft is permitted, as long as they are in a
condition for safe operation. However—
(1) You should contact your local FAA MIDO or FSDO prior to using a
major assembly or subassembly, such as wings, fuselage, or tail assembly from a
type-certificated aircraft. As an amateur builder, you should be aware that when building
your aircraft, the excessive use of major assemblies or subassemblies from type-
certificated aircraft would most likely render it ineligible for certification under
§ 21.191(g).
(2) 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.
(3) All fabrication, installation, and assembly tasks on the Amateur-Built
Aircraft Fabrication and Assembly Checklist (2009) that you’ve completed by the use of
used or salvaged assemblies can only be annotated in the “Mfr Kit/Part/Component”
column."
 
NordicDave said:
Actually this spawns an interesting question regarding USA experimental aircraft.

Keeping the 51% rule in focus. Why couldn't a guy take a quality stripped Cessna airframe with complete empennage and no wings; and then build the wings, windows, interior, avionics, and control cables, etc for the remaining 51%?

Different permutations are possible like completed wings and fuselage, but tail section built from discrete parts.
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Back in the '90s, a couple of locals were developing a Chevy V-6 conversion. They used a Cessna 172 for a test bed. The FAA gave them an Experimental Research and Development certificate for it. They offered to scratch-build wings and tail if they could get an Experimental Amateur-Built license, but the FAA said no. Told them they could get one if they scratch-built a fuselage and re-used wings and tail.
auto C172_sm.jpg

NordicDave said:
A Van's quick build kit has the airframe aluminum complete except the empennage.
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Actually, the airframes aren't "complete"; sample tasks are left to the builder. According to the Van's web page:

Opening the smaller crate reveals a set of wings, completely riveted except for one outboard main skin. The fuel tanks are complete and already pressure tested, the leading edge is attached and three of the four main skins are completely flush riveted. As the builder, you will drill and rivet the one remaining skin, install the control pushrods and blind rivet the composite wingtips to the outboard end. The ailerons and flaps are assembled...In general the builder finishes the inside of the cabin and baggage compartment(s) and installs the [fuselage] skins just forward and aft of the canopy.

After the EAB category was created, a lot of folks took planes like Piper Cubs and modified them extensively. The FAA eventually clamped down on that, using the 51% rule. The Nelson N-4 was an example...J-3 wings and tail.
nelson N-4 in flight.JPG

Ron Wanttaja
 
Van's designed their quick build kits with FAA assistance as to what could be completed by the factory and what could not, so that it met the 51% rule.

As to using a 180/185 fuselage, were you to source a cabin section only, you might be able to do it, but above all, you would need both your DAR and his FSDO to sign off on the plan prior to proceeding. Over the last 30 years, the FAA has really tightened up on what is acceptable. Download the 2011 checklist and run the numbers....
 
wanttaja said:
After the EAB category was created, a lot of folks took planes like Piper Cubs and modified them extensively. The FAA eventually clamped down on that, using the 51% rule. The Nelson N-4 was an example...J-3 wings and tail.
View attachment 108411

Ron Wanttaja
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Wow, that airplane is perfect for someone who really doesn't like to see the ground at all. Or even look down.
 
When assembling a stack of parts to make your own “kit” it’s recommended to talk about it with a DAR first to see if they’ll sign off on it. Whether the airframe could be used would depend on the DAR and how your build plan accounted for it. I suspect it’s been done. In fact there was an experimental 185 for sale recently in Canada that had a Cessna fuse with Cyclone wings and tail. It was going for a very premium price, too.

As for the 51% rule? Per the checklist and scoring formula it would be easy to reach the 51% number while taking zero points for the airframe.
 
My dad snapped this photo at Grants Pass, Oregon, in 2003:

Comoonchey(1).jpg

I did some digging online and found an old for-sale ad for it:

Comoonchey2.jpg

WHY BUILD A LANCAIR, GLASAIR, RV? Here are 4-seats, high-performance experimental, already completeted, testflown and flying IFR, for a fraction of the cost!!!!

Unique 4-PLACE EXPERIMENTAL- IFR Amateur-built (1967 Mooney Super-21E fuselage, Beechcraft Musketeer Vertical fin & rudder, Mooney-Aerostar-based wing, Cessna 337 "Skymaster" rear-engine, Beech tip-tanks). Flown over 1200 hours since first licensed in 1983 by the seller. Cruises 180 mph at 10-11 gph, with 94 gallons fuel. Continental IO-360 at 1930 TT, 206 SMOH, compressions in mid-70ís; McCauley 3-blade about 90 SPOH. With flaps, constant-speed, retractable gear and 200+ hp engine, you can log both complex and high-performance time!

[...] ADVANTAGES OF EXPERIMENTAL over FAR-23/CAR-3 "Certified" aircraft: (1) AD's DO NOT APPLY! (2) Owner can manufacture replacement/repair parts (3) parts traceability not required (4) IA not required to inspect: may be inspected by A&P or certified Repairman (5) Non-PMA'd parts not illegal (6) STC's not required to modify: streamlined process!
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The airplane was lost in a fatal crash in 2006. https://aviation-safety.net/wikibase/45882
 
The comments are appreciated and this is more academic exercise than a build plan proposal.

I can buy a nearly finished set of wings and fuselage from Van's or Glasair and assemble the empennage from a pre-made kit. Seems like if a person bought the pre-stamped parts someone could/should be able to make an experimental aircraft which looks like a Cessna.

To be clear, were not talking about rebuilding a certified plane or cobbling together major certified components from a salvage yard. @wanttaja and @Capt. Geoffrey Thorpe made very good points about customizing certified planes and calling them experimental.

Theory to test:
We haven't seen any Anssec kits (Anssec=Cessna backwards) because Cessna's are expensive to make and a complete set of drawings would need to be reverse engineered if someone were going to sell a Anssec kit. The FFA may lean hard on the rule book to stop the effort as parts may leak like crazy back to the Certified fleet?

Seems like the above doesn't preclude individuals from buying new or quality used Cessna parts and get onto the job of riveting. Use a finished wing set except for flaps and ailerons, complete fuselage except for empennage.

Really curious why we haven't seen more efforts like this or does the FAA look so dimly on an experimental guy cloning a a certified plane they put so much friction in the path to discourage people from trying?
 
Not familiar with the Super Cyclone kit? It's a Cessna 180/185 clone kit. It was founded by St. Just Aviation in Canada and went quiet for a few years. Bushliner aircraft, known for total restorations of Cessnas, bought it last year. I can't wait to hear what the actual build cost of a finished 185 clone will be, but it'll be steep!
 
NordicDave said:
Really curious why we haven't seen more efforts like this or does the FAA look so dimly on an experimental guy cloning a a certified plane they put so much friction in the path to discourage people from trying?
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Cloning has been done for a long time, though the clones aren't always exact. The Wag-A-Bond is a clone of the Piper Vagabond. The Christavia I is a copy, in large part, of the Aeronca Champ, and the Christavia II side-by-side model looks like the Chief. The Just Aviation Cyclone is a cloned Cessna 180. The tube-and-rag airplanes are a lot easier to build than all-aluminum airplanes, especially where compound curves are concerned.

The key is that one has to make 51% of the parts, outside of the engine, instruments, radios and wheels & brakes.
 
The 51% rule doesn’t require making any parts.

To the factory parts question? Nothing prohibits use of factory parts. A builder can’t score fabrication points for those parts. Run the score sheet and you’ll find the 51% score doesn’t require fabrication points. In an approved 51% kit the manufacturer provides the checklist with factory fab points assigned to them. The builder can get assembly points only for those items, and for the list, a point is a point.
 
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NordicDave said:
Seems like if a person bought the pre-stamped parts someone could/should be able to make an experimental aircraft which looks like a Cessna.
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Which would cost a lot more than an actual Cessna... :)

But there is no reason you couldn't do it as long as you score enough points on the checklist. https://www.faa.gov/aircraft/gen_av/ultralights/amateur_built/kits/media/AmBuiltFabAssyCklistFW.pdf

83 page instruction set to go with the 8 page checklist... https://www.faa.gov/sites/faa.gov/f...ghts/amateur_built/Am_Blt_Chklist_Job_Aid.pdf

One difference between yea olde quicke builde kit is that the half a dozen steps that you do on a quick build wing
"To complete this wing, there are many small tasks for the builder to accomplish such as; attaching brackets, a pitot tube, a bell crank, aileron and flap mounts and braces as well as riveting the one remaining bottom skin panel, (see below) the landing light and then attaching the prefabricated flap and aileron. " [page 11 of above link]​
Count as "assembly" and perhaps a little "fabrication" on the kit, but could be considered "repair" of a type certificated part.

I suspect the FAA are being sticks in the mud because they don't want E-AB to be a way around part 43 requirements through a "Rebuild a Wreck" process or to allow you to chop and channel your 172 into an E-AB low rider.

 
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Pilawt said:
My dad snapped this photo at Grants Pass, Oregon, in 2003:
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That airplane was based out of my home airport, in an open hangar just one row down from mine. The third picture was taken there.

Used to have a Stinson 108-3 with "EXPERIMENTAL" in big letters on the fuselage. Not sure what has been done with it.

One thing I've found over the years: If you see a production-type airplane labeled "Experimental" and ask the owner about it, most refuse to talk about it....

Ron Wanttaja
 
wanttaja said:
One thing I've found over the years: If you see a production-type airplane labeled "Experimental" and ask the owner about it, most refuse to talk about it....

Ron Wanttaja
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You mean like this:

7177465628_13969129ea_z.jpg


7177484688_2ff0a0b67e_z.jpg


Guy talked my ear off over it, but you know how those Boeing guys are.
 
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The FAA shut this kind of thing down a few years ago. There was a guy who managed to get several Harpoon's certified as experimental amateur built, despite the fact that Harpoon is basically a Baron fuselage and wings with a single turbine on front. Story I heard was that a single FAA inspector signed off on them, then when someone "upstairs" discovered it, shut the whole thing down. The FAA didn't go so far as to revoke the existing Harpoon certificates, but I think you can be pretty sure it'll never happen again.
 
The 51% rule is currently a joke. As posted above, you can buy an almost complete wing and only have to squeeze rivet a skin and you get full credit for the wing.

Without such absurd rules quick builds and almost all RVs would cease as no one wants to spend 5-10 years on something they can buy for a few grand.
 
pfarber said:
The 51% rule is currently a joke. As posted above, you can buy an almost complete wing and only have to squeeze rivet a skin and you get full credit for the wing.

Without such absurd rules quick builds and almost all RVs would cease as no one wants to spend 5-10 years on something they can buy for a few grand.
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People already spend 5-10 years on some rv's. An Rv10 has something like 23,000 rivets to buck. They give you a bag of parts and directions. It's hardly a "2 weeks to taxi" type program. Which I agree is stretching the spirit of the rule.

I've often thought Piper or Mooney should sell their old models they won't bring back as kits. Perhaps the FAA is why it hasn't or can't happen.
 
Racerx said:
I've often thought Piper or Mooney should sell their old models they won't bring back as kits. Perhaps the FAA is why it hasn't or can't happen.
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More likely economics (or lack of imagination?????). No reason that Cessna couldn't give you a big bag of parts and a book of directions if those parts were not originally assembled into an airframe.
 
It's not 51% of the work or effort, but merely 51% of the tasks involved. One rivet gets you credit for every other one.
 
Racerx said:
I've often thought Piper or Mooney should sell their old models they won't bring back as kits. Perhaps the FAA is why it hasn't or can't happen.
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Why would people buy a Cherokee kit when they could buy an RV kit that has much better performance and doesn't look like every other stodgy old Cherokee sitting on the ramp?
 
Dan Thomas said:
Why would people buy a Cherokee kit when they could buy an RV kit that has much better performance and doesn't look like every other stodgy old Cherokee sitting on the ramp?
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1,800 rivets vs 23,000?
 
If it meets the rule? Get after it and don’t look back. The absolute worst resource for potential E-AB builders? Internet comments from guys who’ve never built one. Hit delete and move on to pireps from guys who have.
 
Since a lot of folks didn’t bother to read AC 20-27G that was mentioned above here’s the relevant paragraphs:
d. Use of Salvaged Assemblies from Type-Certificated Aircraft. The use of used or salvaged assemblies (for example, landing gear, horizontal stabilizer, and engine mount) from type-certificated aircraft is permitted, as long as they are in a condition for safe operation. However—
(1) You should contact your local FAA MIDO or FSDO prior to using a
major assembly or subassembly, such as wings, fuselage, or tail assembly from a type-certificated aircraft. As an amateur builder, you should be aware that when building your aircraft, the excessive use of major assemblies or subassemblies from type- certificated aircraft would most likely render it ineligible for certification under
§ 21.191(g).
(2) 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.
(3) All fabrication, installation, and assembly tasks on the Amateur-Built Aircraft Fabrication and Assembly Checklist (2009) that you’ve completed by the use of used or salvaged assemblies can only be annotated in the “Mfr Kit/Part/Component” column.

Note: The definition of fabrication is to perform work on any material, part, or component, such as layout, bending, countersinking, straightening, cutting, sewing, gluing/bonding, layup, forming, shaping, trimming, drilling, deburring, machining, applying protective coatings, surface preparation and priming, riveting, welding, or heat treating, and transforming the material, part, or component toward or into its finished state.
 
For those that are curious, here’s 2 copies of the Amateur-Built Aircraft Fabrication and Assembly Checklist that’s used to by the FAA to determine if a kit or project meets the Major Portion rule (aka 51% rule). The first one is just the 11-page blank form with the instructions. The 2nd one is the one that Van’s submitted to the National Kit Evaluation Team (NKET) which is the body that validates that kits for 51% compliance. If found to be compliant, then the Kit builder doesn’t have to complete the Fab and Assembly Checklist (Appendix 8 to AC 20-27G, btw)

I can tell you from experience that even though there’s very little fabrication involved with the construction of most RVs, the assembly tasks are still a tremendous amount of work. Those that dismiss this out of hand as some sort of 51% wink wink nod nod with the FAA don’t have a f’ng clue about what they’re taking about.
 

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Our c172 is EXP and have first happens knowledge on subject of converting to exp. FAA uses a 1950s policy still today that basically states certified aircraft, or large portions thereof, can not be converted to exp outside of very specific purposes, and that said conversions must go through STC process and remain in certified domain. This 1950s policy is specifically noted in FAA inspector guidance if such a request is made. As someone noted above, there have been a few that got an EXP airworthiness cert in the distant past, but some were later revoked. As any DAR or FSDO will use the current guidance order, it’s doubtful you would get very far and be stuck with an aircraft not legally fly able. AB category not even a remote option, regardless of 51% requirements, even if you re-riveted everything and put a piper wing on a Cessna. Exhibition cat is really only practical solution, but you’ll have to jump thru expensive hoops…..there’s several related topics online about how best done, but it will likely be cheaper to keep in certified.

the FAA is hell bent on making it very difficult and expensive to convert to exp regardless how old the plane and if parts are still available, even if means planes are scrapped. Before going down this road, I would suggest finding a local DAR with authorizations in the categories you are considering before starting. Good luck.
 
How does the FAA prohibiting this keep the flying public safer?

Rule looking for a problem

Seems to me making a franken Cessna would be just as safe or safer than say a building Hummel bird from scratch, still can’t make money and fly for hire the public in a experimental and the plane needs to be branded as such by the entrance, I don’t understand why the FAA is taking a hardline stance on something like this
 
age old question...... many believe the FAA has no budget for GA and no political pressures except from hobby groups like AOPA and EAA, compared to airlines, and they simply want GA to go away. many legacy aircraft that were scrapped or parted-out over last couple of decades could still be flying if allowed to convert to experimental.

Locally, pilot examiners are close to a 2 month wait and cost up to $1000 for PPL checkride. There's plenty of qualified DPE applicants wanting to perform check rides and they are not paid by FAA, essentially free labor, but they won't add any more. more DPEs would lower checkride cost and expedite pilot training . But FAA don't even want the oversight for different reasons. Less GA, the less their workload and required budget.
 
AlphaPilotFlyer said:
many legacy aircraft that were scrapped or parted-out over last couple of decades could still be flying if allowed to convert to experimental.
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Back again. We've already been round and round why TC'd aircraft can't go experimental amateur built which is what you continue to imply without saying. Its the same reason why Canada went with an Owner Maintained category vs converting to E/AB. Since the Canadian program is exactly what you are promoting and covers a number of those same "scrapped" legacy aircraft, why hasnt the TCCA OM program taken Canada by storm? Why hasnt every private owner who owns an aircraft model listed in Appx H of the link below converted to OM category? You seem to think it will save GA plus give a home to your modification. So why havent those Canadian owners seen what you see?

https://tc.canada.ca/en/corporate-s...compliance-canadian-aviation-regulations-cars
 
just replying to a question posted by member regarding my personal, relevant, current experience with topic. as always, not promoting anything regardless of your insistence that I am.... not sure what your issue(s) are but I find you annoying.
 
FrankBravo said:
How does the FAA prohibiting this keep the flying public safer?

Rule looking for a problem

Seems to me making a franken Cessna would be just as safe or safer than say a building Hummel bird from scratch, still can’t make money and fly for hire the public in a experimental and the plane needs to be branded as such by the entrance, I don’t understand why the FAA is taking a hardline stance on something like this
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you beat me to it.
As I read through this topic just now I was asking myself why the restrictions?
I just can't get the logic slicing it form every which way I can think of....EXCEPT protecting the original builder....and the establishment of certified parts and the rest of it.
I'd have to think about it a bit more to be sure....BUT if I were King of the rules...I would seriously consider the idea that if a person was to disassemble a plane down to it's parts and reassemble it even pretty much as is I would not see that any different really that building a kit like a vans. At that point the builder would know every rivet and every wire splice ... nearly pretty much the same as a scratch builder would but they may not know the engineer and design as deeply...but then neither do kit builders.
 
Somewhere in the internet there's a story about a guy who did just that. He bought a bunch of components from different salvage yards on the cheap in the 1980s; a wing from here, a tail from there, ect. He rewired, re-rivited, welded, fabricated, painted the thing, even installed parts from other types of planes. The local FSDO (or GADO, at that time) initially signed it off for EXP AC, but it was soon revoked due to FAA policy. The guy was stuck with a plane essentially worthless even though it flew fine. I once worked for a company that bought salvage planes and used all the parts to make one airworthy. It remained in certified category. They made a good return on investment, but it was the 1980s when GA all but closed down and planes were being parted out wholesale and cheap.
 
Earlier in this century the FAA revised the policy for building new airplanes from spares and PMA replacement parts, essentially to stop Cubcrafters from producing new airplanes on Piper's type certificate. That forced Cubcrafters to certify their Top Cub CC-18 in part 23. That was an interesting case and the FAA's position made sense. And now just 2-3 years ago there's a new policy about resurrecting "destroyed" airplanes that's made piecing parts together harder again. While it sounds like the FAA is tightening the noose, more and more guys are using the Experimental Exhibition category to fly certificated airplanes with unapproved mods and parts. Where there's a will, there's a way.
 
Stewartb said:
Earlier in this century the FAA revised the policy for building new airplanes from spares and PMA replacement parts,
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The back story to that revision wasnt directly from the FAA. They actually stayed neutral with Richmond/Cubcrafters and others who manufactured new aircraft under the old Part 21 surplus and spares rules. However as part of the GA rescue of the 90s, Congress caved to a number of "demands" from aircraft OEMs and vendors and codified a number of items.

The STC permission letter was one and after several more years of lobbying got TC permission included in several existing laws. The FAA were forced to change 21.6 but with some exceptions. So for Richmond to continue after August 2004 he needed to get a Top Cub TC which happened rather quickly for obvious reasons.

Congress also wanted to codify "destroyed/scrapped" aircraft during the same timeframe but hit heavy resistance from many aviation groups which got that squashed. Regardless, the reason you see the recent FAA Order on Destroyed/Scrapped aircraft has more to do with those nefarious operators who sell junk as serviceable items or swapped data tags to hide an aircrafts history. Unfortunately, you can directly thank mostly helicopter deekheads like Hansen in Guam for that order.

All said and done, there still is a legal path to repair aircraft with extensive damage. It requires a bit more effort but for those who previous followed the rules like Richmond did years ago, its not much of a stretch to continue. The downside now is if you want to build new from surplus and spare parts and want a standard AWC you need a permission letter from the TC holder.
 
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