Earlier, (Jay) wrote:

...Anyone seen anything like this?

It's been common practice in the soaring world for several years; many
if not most current production machines have wingtip extensions
available as options. So you can choose 15 meter span, 18 meter span,
winglets, and things like that depending on what sort of flying you
think you'll be doing that day. It's also handy to remove the winglet
for stowage and trailering.

My HP-24 project is slated to have a standard 15 meter span, with
extensions to 18 meter, including aileron extensions. The gross
weights will be different, but the speeds will be pretty much the
same.

Bob K.