On 12-7-2010 16:48, gliderman wrote:

I own 3 experimental - amatuer builts which I thoroughly enjoy.
However the restrictions on them are no where near as restrictive as
experimental - racing/exhibition.

So I wonder if I "substantially modify" a certified glider (such as
adding winglets or Schuemannizing,) might I be able to successfully
argue that it belongs in the amatuer built category?

Paul G
Nope. There's that pesky 51% rule.