"T o d d P a t t i s t" wrote in message
...
"01-- Zero One" wrote:

No, I'm not saying it can't be done legally. I was
commenting on the conversion process from a standard type
cert to experimental. As far as I can tell, that's
extremely difficult to near impossible. (I'd be interested
in hearing from anyone who's done it.) However, there are
other routes to modifications of a standard certified
aircraft. If the proposed change is a major modification
under Part 43, you'll need a 337 approval or a Supplemental
Type Certificate from the FAA. If not, then it's easy.
--
T o d d P a t t i s t - "WH" Ventus C
(Remove DONTSPAMME from address to email reply.)


I once owned an SGS 1-23 that had had the wing extended. The tip extensions
were removable. Due to this mod the aircraft was converted from "Standard"
to "Experimental, Exhibition and Racing". The most interesting thing about
this airworthiness certificate was that it specifically stated that the
aircraft reverted to "Standard" when the tips were removed. To my knowledge
this "dual certification" was a unique case. This was done quite a while
ago, and by someone (Paul Bickle) with impeccable credentials and very good
FAA contacts.

Modern era "Experiment" operating limitations are supposed to have an item
stating that: "The cognizant FAA FSDO must be notified, and their response
received in writing, prior to flying this aircraft after incorporation of a
major change as defined by Part 21.93". This requirement is the substitute
for the 337. (I personally would seek their advice and okay before
performing the mod to avoid unpleasant, and expensive, surprises.)