On 11-21-2010 16:42, sisu1a wrote:
I don't recall a 337 as changing them to experimental...

337 has nothing to do with EXP/Std reg changeover. It is the number of
the form that stands for "major repair or alteration" and is typically
accompanied by a new weight and balance when major repairs
(reattaching a tailboom for instance) or alterations (like winglets),
although may not be necessarily in every case.

My SZD59 is EXP reg, but I still went the 337 route when I modded my
stock mechanical brakes to a hydraulic Cleveland setup. Didn't need
the w&b for this job, since the part total was within 1.5lbs of the
old setup and that is all predominantly on CofG, but I didn't trust my
old one and wanted to put some weight in the tail, so a fresh w&b was
useful to me to determine how much...

And why exactly do you want to keep the std reg? Do you use it in a
commercial capacity? (obviously not since it has 1 seat...) Exp rating
allows you a lot more leeway with *legally getting your ship/cockpit
dialed in etc. Work that falls somewhere between changing a tire and
needing a 337 still needs to be signed off by an A&P, but a 337 needs
an A&I and is much more involved. Std means anything beyond changing a
tire/simple maintenance level work has to be farmed out to an A&P,
regardless of your skills.

-Paul

Actually, I am not the one who started the thread about going into the
experimental category. The reason "I" would stay in the standard
category is to avoid any restrictions that may come with the
experimental category, such as for exhibition only, etc. I'm pretty
sure going to experimental would place various restrictions on the
flying of the aircraft. Also, going to an experimental certificate
won't eliminate the need for A&P inspections/sign offs. As far as I
know, only people with repairman certificates can sign off work on an
experimental "AMATEUR BUILT" aircraft and then only if they built a
majority of the aircraft. Just putting winglets on a certified bird
would not be a basis to get a repairman's certificate...