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Old September 15th 03, 09:05 PM
patrick timony
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: One reason this does not work is because humans do not have the strength
: to weight ratio for muscle powered flight. Birds are specialized. Even
: their skeleton is porous so the bones are lighter.

The human-powered planes that have crossed the English channel
required something like 2.5 HP (about 2000 Watts). That's about the most
efficient plane you can make that'll carry a person. Try peddling like
2.5 horses for more than a few minutes and see if you'd like to "land" yet

-Cory


I think the HPOs like the English channel one, require so much energy
because they are not using their weight efficiently. The style of
natural flight they are trying to imitate is soaring. I am talking
about hovering flight like a bumble bee or a humming bird or a
butterfly. The butterfly is really important I think because it has
low aspect ratio wings and if you watch them you can see that they're
moving just like a swimmer doing the "butterfly", which is sort of how
I think a human powered stroke would have to work. But I think we are
built more for the crawl stroke or a combination of the breast stroke
and the crawl, becuase our legs are so much more powerful and the leg
stroke would have to support most of our weight. I think the stroke
that would work best would be one that allows the flyer to adjust the
speed and style of each limb to support his body maintaining a certain
position in the air. This would probably look like three dimensional
running. Actually it would probably look pretty much like an
exagerated doggy paddle, if you've ever seen a dog swimming in place
in the water.

All the Ornithopters I have seen on the net are using bird=like or
dragonfly=like wings. I think they should lower their aspect ratios,
start thinking about vertical take off, and use curves, concave
surfaces, and even spirals in their wing design.

Patrick