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Fabrication vs. Construction




Is it going to become a lot easier to meet the 51% rule ? The latest announcements by Cub Crafters seem to permit easier builder fulfillment of the 51% rule.

Announcement of June 22, 2015
http://www.cubcrafters.com/news/88-carbon-cub-fx-builder-assist-program-announced

“Carbon Cub FX Builder Assist immerses new owners in the construction of the aluminum, steel and composite parts that make up the Carbon Cub... “

“Instead of assisting your assembly of parts from a kit, CubCrafters’ technicians facilitate your fabrication of the parts themselves! Using our modern facilities and equipment, we will guide you through the fabrication process in an astonishingly short time.”

“This new program satisfies the FAA Major Portion Rule (or “51% rule”): the builder completes more than half of the aircraft construction described in the Amateur-Built Aircraft Fabrication and Assembly Checklist FAA Advisory Circular 20-27G, Appendix 8 . No technical experience is necessary.”

Also from their website :

FX builders will spend a five day session at CubCrafters constructing their parts and components

Five 8-hour days working with our factory technicians
Steel, aluminum and composite aircraft components will be fabricated and assembled

CubCrafters uses the customer-built components to assemble a nearly-complete Carbon Cub FX

Approximately 50 days after the first build session, the builder returns to put the finishing touches on the aircraft

One day for final assembly and preparation for airworthiness inspection
One day for airworthiness inspection, certification and a minimum of two test flights by CubCrafters test pilots

Here is the link for the FAA regulation and an excerpt of the definition of FABRICATION.

https://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/99737

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.

2+2 = 4. So does 3+1. So are there different approaches to the 51% rule whereby the “builder” can fabricate far “MORE” of the pieces and can therefore do far “Less” of the building? Loading a few tubes and punching buttons on a CNC machine so I can claim more towards the 51% rule sounds pretty good. Future 3D printing may allow all sorts of possibilities in terms of helping to fulfill the 51% rule.

Just SuperSTOL Wing Detail


Backcountry Super Cubs wing detail


Spending a few days in the factory of Just Aircraft in Walhalla, SC, or Bearhawk Aircraft in Atlixco, Mexico might be a means of significantly lowering build time while maintaining compliance with the 51% Rule. I think there is a large segment of wannabe builders like me who want to construct an EAB, but don’t have the time or feel a little intimidated by a first time build. This approach opens things up. A lot.

I commend Cub Crafters for pursuing this approach. I hope manufacturers like Just, Bearhawk, Backcountry Super Cubs, and others, will consider offering this option as well.

For those of you in the midst of building a Bearhawk, SuperSTOL, SQ2, RANS, or other backcountry aircraft, do you have any opinions on roughly how much of an offset the new fabrication initiative might have on reducing the construction % or # of hours, while still meeting the 51% requirement.

Nothing really new here, though maybe taken a bit further. Glass air has been offering a similar program for several years.

Considering you can buy a completed E-LSA Carbon Cub this doesn't seem like too much of a stretch. The rules for E-AB are some different, but......

MTV

Does that mean it cost 51% less then a completed carbon cub?

Cubcrafters has you there for 40 hours. I imagine the old fashioned way would be closer to 1500 hours or more if you are doing everything. That's quite a difference.

I understand that week at CC costs you an additional $20K. If you have the means and desire to fly a Carbon Cub more than build it, then it would seem a fine idea.

Those guys are always thinking. Good for them!

My thoughts are:

With 51% you can also do the annuals.

The idea of 700+ hours to say build a Bearhawk 4 place or Just SuperSTOL kind of pushes it outside of the envelope for me. On the other hand, say 250-300 hours construction plus 40 hours of factory assisted fabrication time to qualify for the 51% rule sounds very enticing. Not having to cover a plane and still qualifying for the 51% Rule would be a major attraction for me.

Carbon-fiber 3D printing of certain parts like wing tips, cowls, avionics front panels, etc. is going to be pretty exciting.

The two weeks to taxi program mentioned earlier I understand still leaves a lot to do. That would be a two decades to taxi for me. The CubCrafters approach seems really innovative,and reduces build time significantly.

It seems that if this option becomes popular, maybe other manufacturers will offer similar programs.

Again,hats off to CubCrafters !

A local builder created an entire all metal wing design and used a ShopBot CNC to cut out 95% of the parts...ribs, spar flats, skins, gussets, etc. He also made all the form jigs for the ribs and other parts on the same machine. I believe the parts were all cut out of aluminum (and plywood for the forms) in a short day with almost zero scrap.

His idea of a kit is to provide G-code files and let people use his machine for a couple days to practice techniques and make all the parts, or let them find their own fab resources (a local laser cutting or water cutting shop, for example). He thinks he will make higher margins charging half the price of a prefab kit than a kit manufacturer will make providing fabricated parts.

He doesn't have equipment to do the other machining, but I've done quite a few structural parts for him on my cnc mill and lathe. He could do the same thing. I've taught dozens of people how to use CNC mills who didn't have any real machining background at all, in far greater depth than what would be required to do factory assisted services as described. (Almost) anyone can do this.

The brake operations are really the missing elements that may prove more difficult.than the other tool.operations. 8' brakes don't grow on trees.

E-AB is the only growth area in GA of any note. And steps to reduce costs for the public like this could become a really big deal for us.

I think CNC and 3D printing will continue to impact kit building, not just for aircraft. The Germans have even made cars with 3D:

http://www.wired.com/2014/03/edag-3-d-printed-car/



I think if manufacturers can help builders with a major portion of the fabrication process, and get the build times significantly below 500 hours, they will access a heretofore untapped segment of the market. A lot of folks just honestly can't devote 500-700+ hours to a kit. It s not a matter of will power, but a reality check.

Just speaking for myself, I am pretty excited about the possibility of actually building a kit if I can get it down to a manageable # of hours. I am not retired yet, I do a lot of volunteer work, seem to be mowing my grass every three days and am logging way more hours on my zero turn mower than in any Cessna these days. 700+ hours just is not reality for me.

A lot of folks who would be first time builders I think would breathe a lot more easily with a high fabrication/ low build time percentage approach for the 51% rule. I have also wondered about resale values of a plane. Given three scenarios, namely scratch built, kit built, and factory assist kit built, which of the three planes would have a higher resale value ? I am assuming that the builder is a first time guy like me and not some Oshkosh EAA trophy-winning wizard.

I see a lot of potential in this approach that CubCrafyers has initiated. Yeah, I was aware that the two weeks to taxi program existed, but the key word was taxi. I had read in several threads that the "taxi kit" still required a LOT of work to complete before "flying". .

Anyway, I hope the folks at Just, Bearhawk, and several other manufacturers are reading this. I think I read that a Rans S6 -ES quick build is supposed to go together in 150 - 250 hours.

http://www.rans.com/#!coyote/c1ibj

BUILD TIME: 350-550 HOURS

QUICK BUILD TIME 150-250 HOURS

That may be a tad optimistic, but if the Hi-Fab approach is used on the S6 ES, could that drop the time to < 100 hours ?

Maybe as I write this there is some clever engineer/businessman crafting up a new design that will be designed around this new approach. Hmmm. a new bigger wider Bearhawk with 50 inch cockpit width, or a Just aircraft 4 place XXL SuperSTOL. ? Hi fab, CNC, and 3D printing.... bring it on.

500-700 hours is FAST. Most cubs get built in 1000-1500.

As far as offering more options to people wanting an E-AB aircraft, these programs are great. But as far as the "builder" actually doing 51% of the build, GlasStar's two-weeks-to-taxi program or Cub Crafters 40 hour you-fab-the-parts program are bullshit IMHO. They have found a way or ways to circumvent the rules, or the intent behind the rules, at least as I see them. I think the FAA is going along with it because they're worried that people who shouldn't even be allowed to hold a screwdriver are gonna try to build airplanes. In the past, the FAA has given the old wink-and-nod to hired gun builders who would do all the actual building, but have the owner sign off as he builder so he can get the repairman certificate-- which is also bullshit IMHO..

Also, I don't understand why a guy can build an exp Cub using any number of aftermarket-produced fuselages, yet he can't do the same thing starting off with say a Pacer fuselage. I'm told that even if you can meet the 51% checklist criteria, the FAA takes an extremely dim view of using a factory fuselage as a starting point. A friend of mine wanted to build an exp Pacer, but after talking to a lot of people including some FAA types he settled for keeping his Pacer project in the certified world. But now, getting all his desired mods approved is proving to be frustrating.

Hotrod180 wrote:

In the past, the FAA has given the old wink-and-nod to hired gun builders who would do all the actual building, but have the owner sign off as he builder so he can get the repairman certificate-- which is also bullshit IM

I agree 100 % on this. Illegal, immoral, and dangerous. The wrong thing to do, period.

Also:

But as far as the "builder" actually doing 51% of the build, GlasStar's two-weeks-to-taxi program or Cub Crafters 40 hour you-fab-the-parts program are bullshit IMHO. They have found a way or ways to circumvent the rules, or the intent behind the rules, at least as I see them.

I think on this one I am a bit split. In one corner you will have builders who truly have the mechanical skills and expertise to fix anything from a leaking faucet to a Swiss Rolex, but don’t have the time, space, supportive spouse, etc. In the other corner is a second group of folks who can’t screw in a light bulb or tie their shoelaces; the ones who need an hour and a half to watch the television show 60 Minutes. For the latter group to do repairs or run their annual kind of gives you pause to think. Of course, if they buy a prebuilt experimental they can still do repairs and mods, just not the annual.

I like to think that the high % fabrication content approach recently announced by CubCrafters will be embraced by the first group, not the second. Perhaps manufacturers can still keep certain limited construction aspects in place to help filter out the truly inept and incompetent from taking unfair advantage of the 51% Rule. As far as the “intent behind the rules”, I like to believe that lowering the # hours for construction down from the 500-1000 to something in the 100 – 200 hour range does not necessarily violate the original intentions.

I used to homebrew a lot of ham radio gear from scratch years ago. I also soldered together HeathKit and Eico radio kits. Back then, Hams who did not build gear or use Morse Code were called appliance operators and not real “Hams”. Tubes and discrete components are now largely history and nowadays Elecraft Electronic modules for example are far easier to construct. Morse Code? Gone like Elvis.

http://www.elecraft.com/k2_page.htm

A ham radio is of course not an airplane, but the fact is technology moves on, and CNC, 3D printing, glass avionics modules and more have now become available. Design and construction techniques change. If a kit snaps together like LEGOS, I am okay with that. If I can get a Bearhawk 4 place or a Just XL SuperSTOL in an advanced kit form and flying with say <150-200 hours of build time, I don’t mind applying under the 51% Rule for doing my annual inspections and mods/repairs.

I just see this new approach as a means of opening up a new segment of builders who just could not realistically devote 500-1000 hours to a project. These “new builders” do not necessarily lack the skill set or knowledge, nor are they trying to unethically circumvent the 51% Rule.

I hope folks like Troy Woodland (Just Aircraft), Randy Schlitter (Rans), Mark Goldberg (AviPro Bearhawk), and others will follow suit with similar options.

It depends on a person's background don't you think? Legalism aside, I think I'm better qualified to work on most aspects of my own airplane than a hired gun with an A&P obtained working military jets or at United. If a guy can read 43-13B with reasonable comprehension, track and follow AD notes and Service Bulletins, manufacturers service information, etcetera......who's to say? Hey? That's the way Canada has gone. They aren't falling out of the sky any faster than usual.

It is a lot of regulations on the Canadian homeowners maintained. I wish they would expand it to allow more planes in...

Mister701 wrote:It depends on a person's background don't you think? Legalism aside, I think I'm better qualified to work on most aspects of my own airplane than a hired gun with an A&P obtained working military jets or at United. If a guy can read 43-13B with reasonable comprehension, track and follow AD notes and Service Bulletins, manufacturers service information, etcetera......who's to say? Hey? That's the way Canada has gone. They aren't falling out of the sky any faster than usual.

Pretty much sums up how I feel about it. There are some fantastic mechanics out there that can do great work on lots of different airplanes. I only have one plane I'm concerned about maintaining and because of that I can learn everything there is to know about how to keep it airworthy.

The regs are petty clear about what work counts towards the 51%. As long as the guy that holds the repairman's certificate did 51% as defined by the regs then who cares if it was fabrication or assembly? It is frustrating that DARs let people get away with hiring out the build then claiming they did the work so they can get the repairman's cert. but that doesn't affect me so I see not reason to stick my nose in their business. If personal integrity is not important to them then so be it.

Whee wrote:

The regs are petty clear about what work counts towards the 51%. As long as the guy that holds the repairman's certificate did 51% as defined by the regs then who cares if it was fabrication or assembly?

Here is a link to some of that stuff:

http://www.faa.gov/aircraft/gen_av/ultralights/amateur_built/kits/media/am_blt_chklist_job_aid.pdf