Re: aktinofibril intercalation, JCunningham

[jrc <jrccea@bellsouth.net>]

Me, I think.  It's not a new hypothesis.  I've spoken of it in talks several 
times, starting in about 1999.  Haven't written anything on it yet.  Due to 
the intercalated nature of the actinofibrils, it would be virtually 
impossible to keep them rigid with respect to one another.  I've not 
attempted to determine likely maximum extension because I don't consider the 
maximum to be terribly important to flight control, but would expect it to 
be on the very loose order of 10 to 20%.  The far more important extensions 
and contractions would have been on the order of fractions of an inch 
(flutter inhibition and also roll control due to the impact on camber).  A 
localized 2% change in length due to differential movement between adjacent 
fibrils would have an enormous impact on aeroelastic number and the bistable 
and flutter limits.  Different areas of the wing can operate somewhat 
autonomously, but not at all like airliners, nor would that be the intent. 
The important effects need to take place over localized areas about the size 
of your hand, but it doesn't hurt if the effects extend further.  It has 
relevance to both the inner and outer wing.  The fibrils are not shorter in 
the inner wing (about 10 cm), but they are more amorphously aligned and not 
as densely spaced.  Note that there is no consensus on this yet.

As an aside, for the broadwing concept, I see no way for the chord of the 
inner wing to be extensible enough to allow for free motion of the hindlimbs 
when launching.  If it is slack enough to allow the rear legs freedom to 
launch, then it will be slack enough in flight to present severe problems 
for both flight efficiency and flight control.  Keeping it taught would 
require limitations on hindlimb mobility in flight that don't seem 
practicable to me.  When the inner wings go slack, the animal will be on the 
ground in short order, whether intended or not.

----- Original Message ----- 
From: "david peters" <davidrpeters@earthlink.net>
To: "jrc" <jrccea@bellsouth.net>; <qilongia@yahoo.com>
Cc: <dinosaur@usc.edu>
Sent: Monday, July 16, 2007 7:35 AM
Subject: Re: aktinofibril intercalation, JCunningham


Jim,

I am familiar with the intercalation. But I don't recall hearing the 
hypothesis, until now, that the fibers moved longitudinally. Who is that 
author of that hypothesis and where is the paper?