Funny you should bring this up. I've been considering a series of very
narrow (high aspect) winglets which would pivot at their roots and be
attached to the end of the wing. These could be arranged to work
together as a very high lift arrangement and be foldable on-the-fly. A
lot like the wingtip feathers of large raptors. Aft winglets might be
shorter than fwd ones, and each "feather" might be only 2-3" in chord.

Jay wrote:
Seems like it might be useful to have removable wing extensions for an
experimental. There are times when you want a fast airplane for cross
country and you can stand a long runway for the high TO/landing speeds
and then there are other times you want the low speed handling for
short field, etc. Flaps do this to some degree depending on how
exotic you want to get and have the advantage of being adjustable in
flight but the wing extensions would appear to extend the flight
envelope (on separate flights) beyond what can be done with typical
flap configurations.

A solid composite structure, perhaps 2 feet on each side that plugs
into the main spar(s) would do nicely to allow you to have both a high
speed clipped wing plane (when removed) and a long wing high lift
plane, of course not at the same time. The further out you go on the
wing the less the loads are so these wouldn't have to be built up as
strong as other parts.

They could be made with no control surfaces or other moving parts.
You could even select a different airfoil for that section if you
wanted. No problem plugging composite extensions into an aluminum
main wing. Of course the main short wing would have to be built to
allow access to the main spar(s). A hollow rectangular cross section
spar could accept an insert to mate with removable extensions.

I guess you'd need some sort of plastic overlay for the airspeed
indicator to remind you of the new critial speeds.

Anyone seen anything like this?