Ornithopters 4: Return to the Eyrie

A few more 'thopter sketches...Now that I've got the basic design architecture pinned down to my satisfaction, I'm more or less just playing with wing designs. I feel like these are a pretty good compromise between engineering and aesthetics in that they look like airplanes but flap their wings like birds. I consider the wingtip feathering very optional in most all of these, so please feel free to mentally omit it if you'd prefer. The numerical sequence at bottom is my solution to the retracted "stub-wing" grounded configuration as described in Dune. With those mechanical pivoting components covered over by the insulating wing sheath, there would be the visual impression of components shifting and bulging beneath the elastic "skin" as the wings extend.

I'm still puzzling over how the Duke's 'thopter lifted off with wings retracted before beginning flapping locomotion, though. Aside from VTOL jet- or rocket-assisted takeoff, the only other solution I can think of is that the ornithopters use suspensor agrav technology to reduce their apparent weight...This would certainly make the whole 'thopter concept much more feasible, especially on the scale of the gargantuan heavy lifters supposedly used to transport spice harvesters. It would also alleviate the need for an equally mystifying preponderance of exotic ultralight structural materials in the wings and body.

I also realized that my old Raiden/Luft '46-inspired attack plane could easily be repurposed as an ornithopter along these lines:
thomastapir.deviantart.com/art…

For whatever it's worth, I am officially dedicating this entire 'thopter series to in recognition of the ongoing, overwhelming generosity he has inexplicably shown towards me...I don't know what I did to deserve it, but I sure do appreciate it!