Welll folks i am fond of reading Randy and here in this piece he
explains my long standing query that why not make all our existing
models composite airframes if it save so much fuel and add to
efficeincy.... so here is answer from someone from boeing.....
C.W. from California recently asked about composite "skins" on
commercial airplanes, as in, why not make all of our existing models
composite airframes?
Given that a 747 or 777 is built around an aluminum frame, how
difficult would it be and how much weight would be saved by
"re-skinning" with the same material that is being used for the 787?
It would seem to be relatively easier to make pre-molded sheets vs. an
entire fuselage .. would this be at all practical?
Well, the answer is, it's not really practical. To get the full
advantage of composites we really have to create the airplane design
from the beginning with the composite "material set" in mind. The cost
of re-doing an aluminum fuselage design that is already complete,
using another material set makes it pretty much prohibitive. I should
add, though, that we are already making significant use of composite
materials in some of our airplanes. 9% of the 777's structural weight,
for example, is composite - primarily floor grids and the empennage
section.
Anyway if you like more insights on what else Randy ha to say
please visit http://www.boeing.com/randy/
