Hey guys. I'm curious if anyone knows how exactly the 51% rule works. what exactly counts as 51%? Is there a chart out there somewhere that breaks the aircraft into % so a guy can figure that out?
Thanks
David

For kits, I understand they have to be certified by the FAA as complying with the 51% rule.

For first of type scratch builds or other special situations, I think they also have to sign it off, on a case by case basis. In that case, I think you'd be wise to get them in at the start, rather than at the end.

I know one guy who was denied an experimental airworthiness certificate because he didn't make "enough" of the aircraft himself. It was a mix of scratch build and salvaged parts. To resolve the issue, they agreed that if he discarded his tailwings and ailerons (which were off another aircraft) and fabricated his own from scratch, he would be compliant. The whole process sounds a little bit arbitrary.

This has all the information you are looking for.

http://www.faa.gov/documentLibrary/medi ... 20-27G.pdf

It's a felony here in Texas to conceal carry in an establishment that derives more then 51% of its income from the sale of alcohol (and has a proper 51 sign posted).

Is that helpful?

The EAA has some great information on it as well:

http://www.eaa.org/en/eaa/aviation-comm ... -airplanes

http://www.faa.gov/aircraft/gen_av/ultr ... ob_aid.pdf

Chris

I began an Experimental 182 project last year. The idea was trashed pretty bad here, but you can catch a bit of the progress on some of the other homebuilt forums.

The approval from the FAA to meet a 51% rule requirement was fairly easy. The proposal was to build a set of wings and tail from scratch with some other alterations. Using the checklist, it gets closer to 60%. All flat and billet stock except bearings, rivets, cables, pulleys, rod ends, etc. The new wing design was static tested last summer to nearly 6 G's to the point of permanent deformation for a 2800 lb planned gross weight. The new wing uses longer flaps and droop ailerons. I hope to reduce the expected stall speed at gross to between 42 and 44 mph. The part designs were designed to be made with CNC machines, and to meet the FAA requirement per the pre-build evaluation, I have movies and pictures showing me running the machines. Because of this, I doubt many people will be interested in the project for themselves. I'm doing it because I can and because I'm learning a ton about a lot of things I didn't have a clue about and so I can do my own maintenance.

The point of all this is the guidelines are a lot clearer than some might believe, both here and elsewhere. Dream a little.

A good place to start:
https://www.faa.gov/aircraft/gen_av/ultralights/amateur_built/kits/media/Am_Blt_Chklist_Job_Aid.pdf
and
https://www.faa.gov/aircraft/gen_av/ultralights/amateur_built/kits/media/AmBuiltFabAssyCklistFW.pdf

Thanks trim tab. I'm thinking a similar project but starting with a 180 and involving cyclone wings. I need to do some engineering for wing loading and power calcs. It'll be a learning experience if nothing else. I'm in Canada, so lots of the faa links aren't much help.
Thanks to everyone for the info and help you have posted. Will keep you guys up to date if a project commences.

A1Skinner

If the project is not on the FAA list of approved kits you have to get a 51% inspection conducted by a MD-RA inspector in Canada. In the past you could use parts from certified aircraft for your kit and received credit, but I am sure this rule was changed several years ago in Canada and parts from a certified aircraft are no longer counting towards the 51% rule.

Heres is the link, look under FAQ

http://www.md-ra.com/en/

3. MAJOR PORTION REQUIREMENT (SO-CALLED “51% RULE”)
Note: All amateur built aircraft in Canada, in order to be issued a Special Certificate of Airworthiness in the Amateur Built Category, must conform to the Major Portion requirement. This can be satisfied in the following ways:

The aircraft is constructed entirely from raw materials facilitated by the use of plans.
The aircraft is assembled from a kit which has been evaluated by Transport Canada or the FAA and found to be compliant with the requirements, and the results have been published on an eligibility list, by the above named authorities.
The project does not meet the above criteria and has been evaluated by an inspector assigned by MDRA and found to be compliant. This evaluation is a one time event and the results apply only to the project evaluated. In addition, if used or commercially manufactured parts are incorporated in the project the provisions of SI 540-001 (IP 549-001) apply (see sec. 4 below and our www.md-ra.com site).
If I have a Major Portion review on my kit, does that mean it applies to all other kits of the same make and model?

No, such an evaluation is valid only for the specific project examined, and none other.

How then is a kit entered on the eligibility list?

The kit manufacturer or an authorized agent must apply for a Commercial Purpose evaluation with MDRA, for publication on the Canadian List. The FAA has a similar process for inclusion on their list.

How does a “Quick Build” or “Fast Build” kit meet the Major Portion?

Only those kits published as eligible can be accepted by MDRA. The “Quick Build” or “Fast Build” version will be shown as a separate entry on the published list(s).

I have a Quick Build version which is not on the published list, what do I do?

On occasion, the standard build version is published, but not the quick or fast build versions. In this event, we will require a separate evaluation for the non published version. Note: This evaluation, performed for an individual builder, is valid only for the project examined, and none other.

My Quick Build kit has some parts closed at the factory. Is this acceptable?

Yes, parts closed at the factory by the kit supplier and indicated as such on the kit parts list are not subject to pre-cover inspection.

Note: We recommend you have a pre-cover inspection done as soon as possible, as the degree of completion of some quick build kits is very high, so you want to ensure that you don’t get into difficulties further along in the project.

I am in contact with a company which will assist me in my build, and they say they can close the aircraft to “Quick Build status” and then send it to me for further work and inspection. Is this acceptable?

No. Only parts closed at the factory by the kit supplier and indicated as such on the kit parts list are acceptable under the legislation.

If I have a very old kit that is no longer listed, what can I do?

We have authority from the minister to accept a kit that was listed, no matter how long ago. If a copy of the publication can be found, we will accept it.

What if the kit supplier is sold, merged with another company or otherwise changes name and continues to sell kits with the original make and model? Or, if the kit is the same, but the name is changed? Are these kits still compliant?

This is an unusual circumstance and will require research and consultation with the supplier and possibly Transport Canada. Please call us for information.



4. REBUILDING OF A CERTIFIED AIRCRAFT AND/OR USE OF USED PARTS.
This subject is covered by a Staff Instruction (SI 549-001) issued by the Minister. This document sets out the rules for use of previously certified or commercially manufactured parts. As a “Rule of Thumb”- start by realizing that the Major Portion rule applies, and the SI does not permit a builder to receive fabrication or assembly credit for such parts, even if work (painting, cleaning, etc.) was required to make them suitable.

So- consider that you must first build the Major Portion of the aircraft without use of any of the used parts. Once this is accomplished, then and only then can you make use of previously certified and/or commercially produced parts.
You can find SI 549-001on www.md-ra.com site.
A Major Portion Evaluation will be required for such a project.

Thanks Pusher. I spoke with the MDRA earlier today, and it is possible to do. I just need to sit down with one of the inspectors and figure out how and what I need to do to make sure I am well over 51%. I plan on doing this in the near future and really am looking forward to figuring out how this is all going to work out.

Have you looked into doing this under Canada's Owner Maintenance category?

Under the O-M Category, Aircraft Pilot/Owners are Eligible To:

-maintain an airplane
-refurbish all or part of an airplane
-overhaul all or part of an airplane
-install certified and uncertified parts
-install or replace any instruments or avionics
-modify an airplane
-rebuild an airplane that is out of service
-sign the maintenance release.

"Modify an Airplane" is pretty vague but I've never researched it too thoroughly.

Jeff

noodles wrote:Have you looked into doing this under Canada's Owner Maintenance category?

Under the O-M Category, Aircraft Pilot/Owners are Eligible To:

-maintain an airplane
-refurbish all or part of an airplane
-overhaul all or part of an airplane
-install certified and uncertified parts
-install or replace any instruments or avionics
-modify an airplane
-rebuild an airplane that is out of service
-sign the maintenance release.

"Modify an Airplane" is pretty vague but I've never researched it too thoroughly.

Jeff

Yup, and no chance. No CS props allowed in homeowners maintenance. Also, there can't be more than 10% of that specific aircraft fleet being used for commercial ops. That pretty much ensures 180 will never be allowed in the Homeowners maintenance category.

David

If you're thinking of a kit plane the manufacturer will pretty much tell you if they comply with the 51% rule. And that rule is just so you can get it certified as EAB. Then you further have to prove you built the majority of it if you want the Repairman cert for the airplane. Otherwise as long as all the components were completed by amateurs for the purpose of education or recreation, then you don't have to build a stick of it. Just have to prove it wasn't built by pro's.

Though to be honest, the two aircraft I built, the FSDO spent more time looking to make sure my placards and markings were correct than going through my build log. They kind of flipped through it and went "uh-huh".

A1Skinner

Here is some more info. You will have a hard time to satisfy the 51% rule with a 180 fuselage and finished cyclone wings. The problem you will have is that you need most of the project parts before you can do the 51% inspection. I would make sure that this will work out for you before spending any money.

Here is the link to the TC Staff Instruction document SI 549-001.

http://www.md-ra.com/pdfs/CONVERSION_SI_ENG.pdf

And here is a short summary.

Transport Canada Clarifies Use of Type-Certified Aircraft Parts in Amateur-Built Aircraft

EAA Chapter 245

Transport Canada’s Staff Instruction document, SI No. 549-001, has been issued to stakeholders, including persons “who apply for a special certificate of airworthiness in the amateur-built classification.”
Although discussions have been ongoing for some time, this announcement clarifies the delineation of the “type-certificated” from the “amateur-built” classifications.

Canadians have been able to rebuild or restore previously certified aircraft and re-classify them as amateur-built. The proviso being that the work done by the builder represented a ‘major portion’ as defined by the MD-RA 51% Amateur Determination Checklist. This SI now clarifies that such rebuilding or restoration is considered maintenance and does not qualify or contribute towards the major portion requirement.

Parts from type-certificated aircraft may still be incorporated into the construction of amateur-built aircraft, but those parts may not be counted towards the construction or assembly for the purpose of calculating the major portion requirement.

A grace period will be extended to those builders who have an aircraft “in the chute,” i.e., aircraft that fit into this category and that have already been accepted under previous policies will be eligible for a special certificate of airworthiness – amateur-built aircraft.

svanarts

There is no repairman certificate in Canada. You can do your own maintenance on an amateur built aircraft in Canada regardless if you have built it yourself or if you bought it already built, even imported from the US.

Thanks Pusher. As I stated, I spoke with the MR - RA and it is possible. I just need to sit down with an inspector and figure out which parts I need to make sure I'm well over 51%. I would get the wings as a kit and build them. Buying completed wings would require some disassembly as an inspection has to be done. I'd rather spend more time and be closer to 60-70% and done right then just trying to squeak by on the rule.

A1Skinner

I have built/building 2 aircraft under the 51% rule. If regulations haven't change recently it will be tight for you to meet the 51%. Go on the MD-RA website and download the 51% inspection form and checklist. It shows all parts of the project evaluated. It is pretty simple and shows the formula how to calculate the 51%. If you use a 180 fuselage with engine, cowling, empennage and landing gear you can not use these parts or related work towards your 51% as they were from a previous certified aircraft. I had a quick calculation. If you use a 180 fuselage with empennage, landing gear, with engine and cowling, no cockpit or interior, build the wings and ailerons from a kit, fabricate/install fuel tank, fuel system components, install instrument panel, fabricate and install seats, fabricate and install electrical system I get 48.2% in your favour. You can improve your percentage in fabricating parts, for example build engine mount and rebuilt an engine from parts or use an uncertified engine and uncertified prop. That will get you over 51%.
However individual MD-RA inspectors interpret the rules differently and maybe in Alberta inspectors are more relaxed on interpretation.
Unfortunately you only know for sure when an inspector will do the 51% inspection if your project will be a go after you have made a significant financial investment. Calling the MD-RA in London is one thing, but you do not know for sure until a local MD-RA inspector has made the determination. Just trying to help you out.

Pusher wrote:If you use a 180 fuselage with empennage, landing gear, with engine and cowling, no cockpit or interior, build the wings and ailerons from a kit, fabricate/install fuel tank, fuel system components, install instrument panel, fabricate and install seats, fabricate and install electrical system I get 48.2% in your favour. You can improve your percentage in fabricating parts, for example build engine mount and rebuilt an engine from parts or use an uncertified engine. That will get you over 51%.

My (FAA, not Canada) plan required the points gained from not using any kit parts at all for the wings. Only raw flat stock or billet, etc., could be used to satisfy a 51% rule. No amount of disassembly and reconstruction/restoration of existing wings would qualify. I wonder how this compares to the Canadian process.

The Cyclone folks did not have plans available some years ago when I contacted them...kits only. This is why I designed my own.

I believe the Cyclone is an amateur built aircraft. As such the wings kit would count towards the 51% rule in Canada. It is the same in Canada if you would use 180 wings and disassemble and reassemble them, this wouldn't count, as the parts came from a certified aircraft.

Thanks again Pusher. I know the inspector well, he is my AME for my current planes. I plan on sitting down with him and going over the numbers and making sure. Over the phone he sounds optimistic. I'd be putting a bigger vertical and dorsal on to deal with handling issues at the heavier weights, and will most likely be going to an O-540 of some flavor. Along with some kind of electronic ignition. At the very least it will be fun to dream, even if the numbers don't work out in my favor.

When I go to my hangar I'll see if I still have my notes on how I got a stinson into the amateur built category about 4 or 5 years ago.. The rules haven't changed since then, so the same arguments I used, should still be valid for your efforts.

If I remember correctly I used the definition from the 51% checklist and the staff instructions of "fabrication"

Note all the procedures that are considered fabrication.

And there was the line "disassembly doesn't count unless significant fabrication is introduced."

We used the definition that an accountant would use. Is the repair/damage enough that we wouldn't get it done at an AMO because it would not be financially viable. That would be significant for us.

Make sure you have the definitions, the staff instructions, and the checklist on hand when the Mars comes in, and you should be ok, as long as you are prepared for the "arguments" that the mdra will make to try to disqualify the aircraft.


Oh yes we also had pictures and text of the 51% approved vans rv quick build kits, which are said to have significant fabrication remaining.

I'll see what I have tomorrow.