Re: Conway's Velociraptor (and pterosaurs)

["James R. Cunningham" <jrccea@bellsouth.net>]

Nice work.  I like your positioning of the foot a bit better than
John's, though I think you both are spreading the proximal tarsals too
much.  My own impression of the flight positioning of the foot reminds
me more of the positioning of a swimming beaver's hind foot.... so that
the camberline has a slightly negative aoa for zero lift.  I think of
the flight function of the foot as a trim servo.

I notice that you are positioning the biological tail to carry an
aerodynamic tail upload, but you have the aerodynamic tail complex
itself (consisting of the hind limbs, the biological tail, and the
uropatagium) carrying a tail download, with apparently inverted camber. 
I would expect the aerodynamic tail complex to carry an upload of about
5 to 15 percent of the gross weight -- which is less than the weight of
the hindlimbs, so the net effect is a structural tail complex download
with the uropatagium lifting upward.  In undisturbed cruise flight, I'd
make the included angle between each tibia about 127 degrees (the
Rogallo angle) for minimum cruise drag.  However, that angle would
actively change to help correct disturbances during flight, so I'm not
faulting the positioning you've used.

Also, you have somewhat more roach than I would anticipate in the
outermost wing.  With that much roach, the maximum rate of curvature of
the semi-ventral cupping in the skeletal spar and the patagium would
move outboard past the 45% point where it usually seems to occur in the
azhdarchidae.  I'd also expect the actinofibril patterning in the front
part of the outboard planform to run more spanwise, increasing the
aftward rate of curvature when they reach perhaps roughly 80% of chord.

All in all, very nice work.

All the best,
Jim Cunningham

Aspidel wrote:

> It's the kind of model I use from now on for my pterosaurs restorations:
> http://dino.lm.com/images/display.php?id=1287
> http://dino.lm.com/images/display.php?id=1332
> 
> Cheers - Aspidel.