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Re: Screaming dromaeosaur biplane killers of the air



Jaime A. Headden wrote:
> 
> I think that for a power take off (jumping in the air and flapping up)
> requires the advanced pully system as a component of the power flapping,

It doesn't.  You simply don't flap 'up' till your airspeed builds. 
Think about flying a J-3 with a 65 hp engine, how you have to remain
level after lifting off till your airspeed builds from about 43 to 60
before you begin your real climb. Even then, you don't flap 'up', you
simply keep your thrust coefficient relatively high and let your
airspeed build.  Since lift increases with the square of the airspeed,
pretty soon you're going up pretty durned quickly. The key is finding a
way to launch that doesn't require a lot of mad flapping.  Long,
powerful legs can be of some assistance in that regard.  I think maybe
we're not considering all the options available to our animals.

> as you note, and that without this (or a rudimentary version of it, as in
> *Archaeopteryx*) or the keel that anchors the large pectorals that
> provides the aerobic down thrust, *Archaeopteryx* is like a swan on water,
> running to gain lift to take off.

How about the possibility of leaping to take off, in lieu of running?
Anyone considered it? This came up during discussion at the Ostrom
Symposium and seems quite promising. And what is downthrust? Is it
anything like lift?

> I have little to say that if it flew it
> was minimally and it seems to be a well-adapted glider transistory to
> flapping flight,

It seems to me to be a well-adapted flapper with poor gliding ability.
Pigeons are poor gliders, and they glide about 50% better than archie,
assuming a non-cascaded tail. Are you saying the tail cascaded?