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Old September 18th 06, 02:41 AM posted to rec.aviation.homebuilt
Roger (K8RI)
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Posts: 727
Default Home Built 51% Rule Under the Gun

On Sat, 16 Sep 2006 17:44:15 -0400, "Kyle Boatright"
wrote:


"Stache" wrote in message
oups.com...
Committee To Review 51% Rule
Government, Industry Partnership To Review Amateur-Builder Statutes

The FAA is concerned that some builders-for-hire and commercial
"builder's assistance" providers are doing more that the FARs permit
when it comes to amateur-built aircraft.


According to the FAA they can do a lot. So those abusing the system
are apparently constructing major portions of the project without the
builder being involved.



snip

The Committee will meet next in November in Washington, D.C.


I'd say the 51% rule is in no danger. People who set up professional build
shops, and their customers are the ones who will suffer. Rightly so, IMO.


The FAA clarified the rule earlier this year by saying: When they say
51% they do not mean the builder actually does 51% of the labor, but
(and they clarified that by saying. If the builder does one aileron
then they know how to do an aileron and some one else may build the
other.) The basic tenant was the builder learn and do the building
requirements. OTOH it's difficult to build half a stabilizer on many
planes like the G-III where the horizontal stab is one piece when
finished. OTOH in the jump start kit the ribs are already bonded to
the top shell (bottom as jigged) and the stab is about ready to close.
For the first time builder of that plane it saves a lot of hours.

Even the builder's centers can legally do well more than half the
physical labor IF the purchaser does over half the items. I'm trying
to find a better way to phrase that, but it gets back to multiples of
the same item. If the builder does one of ten identical items they
said that met the learning intent. IE you don't learn much more by
building 10 of something than you do building one. Most of the
learning comes with the first. I'm trying to remember but I believe
they also said it's OK to use the existing/factory fixtures in which
to construct the parts. I've probably spend at least as much time
building fixtures and I have on the airplane.

At any rate the problem comes from those centers that go ahead and put
the structural members together without the actual builder/owner being
involved. Such as that aileron. The center can have an employee work
with the builder showing him/her how to do the work and the builder
does that one aileron. The center can then go ahead and to the other
one. It gets sticky when we start talking control surfaces instead of
ailerons, flaps, elevator, and rudder if they have different processes
in building them. If I build one aileron and the builder's center
constructed the other I'd probably end up with an asymmetrical set of
ailerons that would require some strange rigging to get it to fly
straight. :-)) OTOH I may end up with that situation with me
constructing both.

Most of the quick build kits sort of follow this route, but supposedly
with a margin for the builder, built in and most of the jump start, or
fast build kits have been checked out and OK 'd by the FAA.

I could legally hire some one to put my G-III together working in my
shop and doing it under my direct supervision (IF I could afford it,
which I can't so we don't need to go there)

When it comes to closing things like the horizontal stab, elevators,
and wing, I will have, and have had at least two others helping. By
the time one person finished putting in all the resin/mill fiber mix
so they could close, the first part would have already set up. It has
to get really cold in there to have much more than 20 minutes to gel
time. If it's near 70 F I only have about 15 minutes. Knock five
minutes of each for available working time. More than once I've gone
to add a bit of resin to a spot only to find a big gob of snot hanging
on the brush. Twice I've come up with the mixing pot firmly attached
to the brush.

So when my helpers arrive we go through the steps of what has to be
done and how to do each step. Then we go to the resin mixing. I
determine how much each person will mix and usually measure out the
resin and catalyst. I show them the mixing procedure, I have the
necessary mill fiber for each in a cup, the Cabosil in another plastic
cup, and the last thing before starting is to fill three syringes to
the proper level with catalyst.Then we work in unison. Add the
catalyst, stir 30 seconds following my procedure, add a measured
amount of mill fiber, stir in, add some Cabosil, stir in, add more
mill fiber to the proper consistency and stir. If need be we add more
cabosil, but each batch gets the same amount of everything. We also
work from the same can of resin and the same bottle of catalyst. I
have good quality masks with activated charcoal filters for each
helper as the fumes from catalyzed Vinyl Ester Resin are not at all
good for you even if they do smell good. OTOH if the day is right with
the temperature about 65 to 68 with a light to medium breeze I'll open
the big doors and we may work without the masks

If need be I do a small sacrificial batch before we start so any one
who has not worked with the stuff knows what to expect. Even then I
try to build something out of that sacrificial batch and work until it
starts to gel.

The builders center can do the same thing, but they can show the
builder the best method for mixing as well as the best mix and
procedure. What took me many hours to develop they can impart to the
builder in a few minutes. They and the builder may then work together
constructing that part. This approach saves many hours. They also
know many short cuts to save time that the builder might stumble on if
they were lucky. That and they can work FAST!

Doing this can leave a fine line between what can and can not be done,
but "I think" the shops giving problems are going far beyond the line
leaving little doubt.


KB

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com