As far as I remember the birds that glide well have thin, heavily cambered airfoils, a bit like those used in the old days on full-size aircraft. Never been a smashing success when built in cantilever form, for aircraft (possibly with the exception for some extremely slow-flying model gliders). But what birds have are excellent autostabilisation, they can feel the slightest thermal, they can vary camber in flight, they can vary span a bit and vary sweep a lot, and have numerous flow control devices, on their wings, et cetera. Gulls, Gannets and ducks even use their feet for aerodynamic control when flying slow, and all is packed in a very light packet, that is self-repairing, except when suffering from age, man, or other vermin! I have flown my THL with a gyro, and that makes it able to fly in very windy and blustery conditions (15-25 mph with ease), and an more effcient flying wing could possibly fly as well as any gull, but the problem is the control and the dragless power-on-demand system. An electric version of the ornithopter flown in Toronto might be the solution, but that isn't dragless, nor does it use a birdlike airfoil (all tries with such airfoils on ornithocopters have been failures, as far as I am aware). Neither can it vary its sweep, and it does carry a fin (no birds do that, as you know), et cetera, et cetera. And the flapping mechanism is drag-producing, as parts of it is external, and there have to be various dragproducing holes in the fuselage (bird's have very small ortifices :-). On the other hand birds can NOT dynamic soar at the speeds seen at Parker Mountain when Joe is there! Yours truely, Tord, Sweden *'`'*.,.*'`'*.,.*'`'*.,.*'`'*.,.*'`'*.,.*'`'*.,.*'`'*.,.*'`'*.,.* -- If reply difficulties - use [EMAIL PROTECTED] Tord S. Eriksson, Ovralidsg.25:5, S-422 47 Hisings Backa, Sweden RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED]
