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Re: Flight capablities of Archie & Confucius? Not so good...



> >  If archaeopteryx lived at
> a beach, and if there was a reliable sea
> >  breeze, it would not need to flap to fly.
> > 
> >  Beaches are excellent soaring locations for hang
> gliders, many
> >  renowned for the # of days per year that they
> are soarable (some over
> >  2/3).
> 
> This sounds plausible, but is it possible with a gap
> between each short, rounded wing and body?

All I can say is that it is possible with an aspect ratio of 5.5, and a wing 
loading of about 7.3 to 12.2 kilograms per square meter, as this describes the 
typical hang glider that soars beach dunes.
I know in the past, the sink rates and aspect ratios were even worse, but I 
also know it was an exceptional day that those gliders from the 70's were 
actually able to ridge soar - and that is ridge soar some sizable beach 
dunes/sand cliffs, not the 1 meter ridges gliders may soar today with only a 
5.5 aspect ratio.

What are the estimates for Archie's wingloading?

As an unpowered flying enthusiast, I think perhaps too much emphasis is put on 
flapping, and not on a wing that simply allows much maneuvering in flight.
The wright brothers solved the "control problem" first.
Animals like flying squirrels, I don't think they can maneuver in the air too 
well - minor course adjustments are all I see in the documentaries.

There are many places where flight is quite possible, even easy, even with very 
inefficient wings and relatively high wingloadings.

Our comparatively inefficient hang gliders actually end up being downright 
*practical methods of transport* at some beaches.
I could easily imagine a species with a very narrow geographical range, 
incapable of powered flight, flying all the time up and down a beach looking 
for food.
Right now, there are several beaches (that I know of, who knows how many more 
that I don't) where the ridges are small enough that walking to the top is not 
a hassle should one land on the beach, and there are 5-10 or more miles of 
soarable beach.
For example there are about 6 miles (10k) of Monterey bay, California,
part of the day just flying back and forth the whole 6 miles for the better 
part of the day. There is even more beach that one could use, if it weren't for 
legal issues.

It seems to me that being able to scan 6 miles of beach, over half the day, for 
almost no energy cost, would yield enough food for Archie.
(heck, if one was willing/able to eat raw Jellyfish, and had fairly good 
eyesight a person could probably feed them self this way)



> 
> >  Some sort of land sail wings? I am not aware of
> any terrestrial
> >  animal that uses wind power to get around like
> people do in land
> >  sailing races out on dry lakebeds in the desert,
> or kite surfers with
> >  skateboards on land.
> 
> Wouldn't that require a vertical sail instead of horizontal
> wings?

Well if you hold your wings outward horizontally, and twist your wrist...
Or if you have a very flexible shoulder....
Yea, I doubt archie did this, I'm just speculating if an animal might ever do 
this- the lack of wheels limits it on land (unless it is ice covered).
I wonder if a duck's shoulders are flexible enough for it to sail around on the 
surface of a lake using one of its wings.
I'm really just speculating "way out there" on what a wing could be used for, 
other than gliding/flight, and the already proposed things (insect traps, etc)

> 
> >  Perhaps a variant of WAIR, where the wings just
> helped it run up a
> >  hill/dune faster with a tailwind, and maintain
> its balance when it
> >  runs down a hill/dune? It could be useful at
> some coastal dunes I
> >  suppose.
> 
> This runs into the same problems as WAIR in general: it
> requires a complex wingstroke that's unlikely to evolve from
> scratch, 
I was thinking of not using any wingstroke, just wings held out with about a 45 
degree AoA to the wind, so the wind "pushes" an animal up a slope.
If you scurry up and down sand dunes all day, particularly if the sand is 
really loose, it could save some energy...
Again, I know it is "way out there" speculation