51% rule

On Fri, 25 Jul 2003 09:30:10 -0500, "James M. Knox"
wrote:

"Bill Daniels" wrote in
:

I was shocked to see a Schweitzer 2-33 glider with a homebuilt
airworthiness certificate. The glider was assembled with parts from
two or more gliders and recovered with new fabric. There are a few
strange but trivial modifications to the original design but it is
still a 2-33. It's very hard for me to see that the rebuilders did
51% of the work. Yet it has a homebuilt experimental airworthiness
certificate.

One note on that... the rules changed some years back. It used to be
that you had to do 51% of the work. Now you only have to do 51% of the
TASKS, i.e. the number of different things required to build the craft.
That is what has allowed all the "quick build" kits to be legal.

For example, you don't have to make 200 wing ribs. You can make ONE
wing rib, and the factory can make all the others, and it counts the

I thought I'd had lots of practice with fiberglass when I started, but
although my early work was plenty sufficient and strong, it's easy to
see the difference between my early work and the current.

same. The theory being that the homebuilt rule is there for education,
and you don't get much additional learning making wing rib #183. G

So it's *possible* to do a *lot* of significant things to an airframe
and meet the 51% rule, even though it looked like the plane was pretty
much there to begin with. [Some "quick build" kits have the basic wings
and fuselage halves already made. Stick those four parts together and

I think you will find that the "Jump Start" Glasair-III has a lot more
than that. (Unfortunately I can't get the Newglasair site to come up
today.) As I recall the fuselage halves are joined, the fire wall is
in, and the engine mount reinforcements are done. The wing is ready
for the flaps and ailerons and the horizontal stab is about ready to
close. They save you about 1000 hours or so... However considering
the G-III is one of the most labor intensive "kits" out there, you
still have a long ways to go.

A little more work and I'll be up to the point where my G-III will be
as far as a "Jump Start" kit out of the box. sigh Course, mine
didn't cost any where near what the Jump start kit does and I have an
engine and prop.

Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)
it looks like an airplane - but there is still a WHOLE LOT of work left
to do.

As someone said, it's all about finding a friendly FSDO.

-----------------------------------------------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
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