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Project: Citabria 7 GCBCrebuilt in the experimental category

It's not actually an air spring doing the supporting. It works pretty much like a Piper bungee/hydrasorb unit except instead of using an oil shock it uses a piston in a housing with air escaping through a calibrated orifice to control the rate of shock extension. No oil or valving, just air being pushed out (and back in on shock retraction) through a small hole. Very simple but works surprisingly well.

Now I have another winter project!

I've got the tubes and bungees. Time for an experiment on air damping. I gave up on the oil damping idea and only briefly considered air damping—which is odd because every time I let go of my storm door I admire the hissing of the door return.
 
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Hi Crash

As i said before, the deal is so good on the Citabria that there is no way that i could built a cub for the price that it will cost me to built myself a highly modified bird, remember, as homebuilder, it only cost the price of the materiels, nothing for certified manpower and there such a nice choice of avionic stuffs today for the homebuilt
market, it must make certified aircrafts owners jealous.
 
I can get a N-Number for a 7GCBC that has the Scout wing extensions. Then order records from the FAA that should include the Form 337 related to that mod. Might help.

Gary
 
The aircraft i'm buying have the wood spars, i need to rebuilt the wings, i'll do it in the experimental or amateur category if you prefer, it is easier to do in Canada than the US, so it is going to be a 36 + ft wingspan from either d&e or from Nick Smith in Ontario, Ca.

Franky
 
If extending the wings consider duplicating the Scout's vertical stabilizer. It varies from the 7GCBC by having the leading edge extended full height. The rudder has reduced chord at the top to compensate. Add VG's to the wings and tail for better control.

Gary
 

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Thank's Gary

Yep, that's all part of the plan + a suspension type landing gears, floats and maybe an O-360.

Franky
 
I know there are restrictions to flying a Canadian registered, owner maintained, certified aircraft in the U.S., what restrictions would there be to an Experimental from Canada that does not fit the U.S. 51% rule? Using a certified fuselage will not apply to the 51% rule in the U.S. in most cases so I just wonder about restrictions crossing the border.

Marty57
 
Xtra fuel for a O-360 and especially floats....I only flew an 8GCBC on wheels and skis. It had the 70 gallon fuel cells in the wings, and at that time mid-70's there was no L<>R selector just ON-OFF. I like the L<>R option. Unless kept coordinated it would drain the right wing first. Then a heavy left foot was required to get the left to drain. Also there were a check valves in each wing (I think between tanks but don't recall) that would not always flow properly. Gas cap gaskets needed to seal at all temps (they shrunk in the cold) so we put fuel valve lube on them.

Anyhow after all that I'd ask around about maybe a belly tank for fuel versus extra in the wing. That would keep the option for only 35 gallons for short trips or a loaded belly which would keep the lateral CG closer to the fuselage centerline. The wings get heavy when all the fuel is out there.

Gary
 
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You have to meet the 51% requirement rules, if you dont, you will not be able to fly it period, that is why i will do a lot of mods on my project, and this need to be addressed before building anything with a DAR.

Now, just think about the kits wich are sold with a fully welded fuselage or pretty much complete if they're made out of composites materiels, you still have to meet the 51% rules, so a fuselage in itself, is not half of the plane.

As for crossing the borders, i dont think it should be a problem, Customs do not know how you've build your airplane, in my case, it will not be called a Citabria, i have to call it something else, we dont carry a list of the components used in building ours airplanes once the project is completed and we've been approved to fly.

Franky
 
Another reason for going experimental, we can come up with a better fuel design.

An extra fuel tank? i'll keep that in mind.

Franky
 
Franky,
The issue isn't using a welded fuselage in your project; it's if it is from a certified aircraft or not. Assembling an EAB from welded parts is done all the time; Javron being one of the best examples. The difference is a Javron fuselage never was a certified aircraft part; the Citabria fuselage is a certified part. Doing mods to a certified fuselage does not move the fuselage into the EAB category. As an example, if I use Super Cub ailerons on my 2+2, the work done covering and painting the ailerons will not contribute to the 51% rule. I can buy non certified parts, assemble an exact clone of a Super Cub aileron, and that assembly, covering, and painting now counts toward the 51% rule. Regardless of how we perceive that logic; we have to work within those confines. Same holds true for a wing built from non certified parts vs PMA'd parts. Just replacing the wood spar with aluminum spars might be ok but best to determine that before committing to that wing. Mods to the fuel system will not move the fuselage from a certified part to an EAB eligible part for the FAA 51% rule. I understand your intent and desire to have an EAB Citabria so you can do what you choose as far as mods but, the FAA will not make it that easy for you. You really should sit down with a DAR and go over your plans with the 51% checklist in hand before starting so as to avoid having an aircraft that is either non-certifiable or very restricted in its use. Check with the EAA; there is lots of literature on the very subject you are attempting. One of the reasons the FAA and the EAA developed the 51% rule and the checklist was to stop the process of moving certified aircraft to EAB; something that was done for a while years back. I'm not being critical of your idea or desire; just that convincing yourself that you have built your own aircraft and convincing a DAR and FAA may be two completely different things.

Marty57
 
Javron, Backcountry, Piper, Citabria. An Exp builder doesn't get a fabrication point for any but can get an assembly point for all. And 1 point is all that's at stake. There's a lot more to the 51% than the airframe.
 
Probably doesn't happen as much as it used too but DAR inspections can be subjective. May not be right but I know of a couple of certified airplanes that morphed into EAB's in the mid 90's. I have been present when the DAR showed up to inspect an EAB scratch built biplane and sat down at the provided table with all the necessary documents lined up and barely looked at the airplane. He did look at all the paperwork thoroughly though. Whats important to one is not to another. We will never have a level playing field, what works for one is rejected for another. In EAB airplanes everybody has to find what works for them but I recommend starting out with getting acquainted with the DAR you plan on hiring to bless your EAB. AC 20-27G is lengthy and detailed, enjoy the quiet time to read it all. I believe the OP said he was going to build in Canada and they play by different rules. Sounds like a cool project Franky, post lots of pictures when you get going. That Super Champ in NZ looks like a Cub eater.
 
Stewart's right, you don't get any points for the fuselage regardless if it's previously certified or not unless you (the builder) built the whole fuselage yourself. If you're accepting that you are not building your own fuselage it can still be a 51% amateur built experimental aircraft but you have to just do other things like assemble the wings, covering, rigging, ect. Lots of points on the checklist that are not related to the fuselage structure.
 
Guessing here, but I doubt Marty 57 has gone through the 51% checklist or airworthiness inspection yet. What guys think before and after that process is usually different. I blame the internet.
 
Marty

I know and i understand exactly what you mean, the main point is that i'm not dealing with the FAA, i'm dealing with TCA (Tansport Canada) and EAA Canada.

Go on Google and type: Transport Canada Recreational Aviation, scroll down the page to General Information and click on "STD 549-Amateur-Built Aircraft and read
section 549.5, it's talking about parts from a certified source, a one place it's written that a welded assembly can be used, a tubing airframe is definitely a welded assembly.

Now, in order to be able to used an airframe as the base for the construction of an experimental aircraft, the donor aircraft need to be de-certified with Transport Canada, it then become a bunch of parts, it is not anymore an airplane, that is the first step, then you need to meet an MD-RA (the equivalent of a DAR in Canada)
and describe to him your project, he will go with you through the whole 51 % list to see if you will meet the requirements, at this point, you are not any worse than an aircraft kit wich come with a pre-assembled fuselage and even a pre-assembled set of wings, a Cub kit from BBI Aviation (Nick Smith) or a Zenair 701 kit are good samples, the 51% rules need to be met, that is the most important thing.

From a Transport Canada standpoint, it does not make a difference if the fuselage come from a kits company or from an existing aircraft, they actually like it, it is an improved safety factor, they know that the fuselage is sound and will not failed, does this go again the idea of promoting aviation? Absolutely not.

You guys with the US EAA should start to pressure the FAA regarding this issue, they are definitely not promoting aviation by rejecting that idea, and i can not understand the reasoning behind it, i can not see ONE negative reason in accepting the use of an existing airframe for building an amateur aircraft, there is definitely an improved safety factor by doing it, it does not hurt anybody.

We've talked to the Chief MD-RA for the province of Quebec about this project and as long as i can meet the 51% requirements, it can be done, i i've done one mistake about it, it's to have called it a Citabria project, it is not, i'm not allowed to use the name Citabria anymore, i'm thinking about calling it an X-Scout.
 
Just a little update here, i bought a set of aluminium spars, they were made locally by a guy name Claude Guilbault, a former CL 215 and 515 (Canadair fire bomber) he pass away a few years ago, they are the same as the Piper Super Cub but the spar cap is much thicker, they are supposed to be good for
3500 lbs but i will limit myself to 2500 lbs.

Retirement is coming next April, i will start the project around September 2022, i have a Jeep project to finish before and i want to fix a few things on my garage before beginning the plane.

I will definitely go for a 36 1/2 foots wingspan, move the ailerons outboard to the max and increase the flaps area to the max as well, VG are in the plan too, i will look at a cuff similar to the Horton stol kit made for the 180 and 185, i should be closed to SuperCub capability with that, while retaining a little
bit of the top speed of a Citabria/Scout.

With the inflation rate going on at the moment, i'm very tempted to order an avionic package (Dynon or Garmin EFIS) ASAP before the prices go up, i'm an ATPL helicopter pilot flying an Agusta 139 helicopter and i'm used to EFIS, i will get rid of the old gauges and the vacuum pump and save a bit of weight.

Franky
 
A couple points here. I’m a DAR and deal with this all the time. If a part was previously installed a a certified airplane (doesn’t matter what type of certificate, Standard or Experimental), any work performed on that component is considered Maintenance, not assembly or fabrication and can’t be counted towards the “major portion”. Now, using PMA parts, if they were never used in a previously certified airplane, installing additional stuff, modifying, or finishing can be counted (but not the fabrication or assembly of that PMA item). An example, you buy a used PA-18 fuselage. You now replace longerons, install controls, cover it and paint it. None of that work can be counted. On the other hand, you buy a PMA fuselage. You can’t count any of the fabrication and assembly of the fuselage, but the installation of systems, modifications, and finishing can all be counted.

The way you count your work is with this checklist https://www.faa.gov/aircraft/gen_av/ultralights/amateur_built/kits/media/AmBuiltFabAssyCklistFW.pdf

Now, for crossing the boarder, every US Experimental certificate states that the aircraft does not meet the requirements of ICAO Annex 8, and that the pilot is required to obtain permission from the Foreign CAA before entering their airspace. I suspect all Canadian experimental and owner maintenance certificates have a similar limitation, so they would need to contact FAA for authorization prior to entering US airspace. I don’t believe clearance from ATC qualifies for this. I’m pretty sure you need to contact Flight Standards or International Flight Standards to get this authorization, but not 100% sure.
 
Flying Amateur-Built aircraft from the US into Canada. or vice-versa, is a simple paperwork exercise. But if you have a Sport Pilot license (US) or a Recreational Permit (Canada), then you're out of luck no matter what you're flying.
 
Can the Citabria fuselage take the weight and stress the Cub fuselage can? For some reason I thought the design was the weak point and the reason for the low weights.
 
dgapilot

You are right with yours comments, the 51% rule apply, no matter what but it can be done and it's been done before.

NunavutPa is also right with is statement, i'm ok, i have a Canadian commercial fixed wings license, a
Canadian ATPL commercial license, US commercial fixed wings and commercial helicopter licenses and a UAE ATPL helicopter license..

md11freighter, i share your concern about the Citabria airframe, the tail section in particular, the landing gear also, theses are points where i will do some modifications, i've read somewhere that the Citabria airframe is heavier than the cub one, the cabin section is quite strong, the steel tubes are supposedly thicker than the cub one.

Franky
 
Update on the 7 GCBC project

Thank's Gary

Yep, that's all part of the plan + a suspension type landing gears, floats and maybe an O-360.

Franky
Hi guys

Retirement did come on, however, i'm still flying helicopters commercially once in a while.
The project is starting, i've bought a small milling and a lathe, i've put my hands on a set of amphib floats, they were built by Claude Guilbault, a former
CL 215 and 415 fire bomber for the Quebec Government, Claude also was an active aircrafts builder, unfortunely, he died many years ago, the floats are not completed, i will need to come up with a gears system for it, all the attachments, spreaders bars, ect.

I've also put my hand on a new set of super cub wings spars, designed and produced by C.Guilbault, the spar web is 0.090 thick as compare to 0.080 for
the S Cub, the spar cap is also much beefier than the standard S Cub, there are supposed to be good for 3500 lbs but i will limit myself to 2500 lbs on my projected wings, i've scratched my head a lot on how to improve the 4412 Citabria wing for at least be able to do what a Super Cub can do and i finaly made up my mind on building a Bearhawk Patrol wing, i've bought a set of Patrol plans before Christmas and made my master rib a few weeks ago.

So, this where i am for now, it will be a Citabria fuselage with a few mods with a , i 36 fts Bearhawk Patrol wings, i hope to be able to be in the Bigs Boys SC Club with the final project.

Stay in touch, i will keep you updated with the developments.

Franky
 
Update

Hi guys, here's a few photos of the stuff i bought, i also bought a set of plans for the Bearhawk Patrol, not sure if i will build the wings at 33 or 36 feets of wingspan,
i need to have an engineer to look over all that, the Guilbault spars are overkilled but i need the expert to tell me if i can used them.
 
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