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My informant is Elizabeth R Dumont, U Mass Amherst.  A representative publication.... 

Dumont, E.R. 2010. Bone density and the lightweight skeletons of birds. Proceedings of the Royal Society B, 277: 2193-2198. 

Steve Vogel 

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Welcome to the airplane of the future | SmartPlanet


(courtesy of David Knight)
http://www.smartplanet.com/blog/science-scope/welcome-to-the-airplane-of-the-future/13456?tag=nl.e660

It's all very well talking about a fuselage designed like the struts inside a bone, but (a) the bone still has a shell, the struts are inside; (b) the bone is essentially internally triangulated  The fuselage figured in the smartplanet blog looks more like a mechanism!  Are we in kingfisher/shinkansen country?? 
 
Perhaps more seriously - the wet dream of aircraft manufacturers used to be knitting the shell like a sock, extruding the structure.  At least that had the possibility that the tensile elements were in the right place.  What's the chances that a fuselage can be produced by RP?  I haven't seen any relevant data on bird bone, but the fracture properties (production of long splinters, etc) indicate that the structure of the bone is highly orientated along the shaft.  Reduction in the amount of material has to be predicated on much more careful design and analysis of loads.  It's taken 25+ years (about a generation) to get carbon fibre accepted into aircraft design, and I'm told that even then the calculations are more relevant to a metal structure.

Julian Vincent
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