51% for the 787 will be carbon fibre. A composite is actually several materials cured to form one. Adobe bricks are actually composites. They are mud reinforced by straw. Boats, surfboards are composite. In aerospace, the first to be used in commercial transport was polyester resin and fibreglass. It is still used today however the polyester was replaced by epoxy resin. The fabrics involved are fibreglass, Kevlar, carbon fibre, carbon fibre w/ boron and carbon/carbon. Initially wing fairings, canoe fairings or "secondary surfaces" were the areas subject to its application. The spoilers of 747's from its inception were fabricated from aluminum honeycomb laminated between layers of aluminum. This method, also considered composite. During the design of the 757, 767, Carbon fibre entered the picture while its use or applications grew on the airframe design. The dive brakes or spoilers, wing fairings, wing lower panels, engine cowlings, rudders, ailerons, etc, saw all composite fabrication with obvious much success. The first Boeing "primary structure" to utilize composite technology was or is the 777 vertical fin. Most of the above mentioned structures are nomex honeycomb core or "resin impregnated paper". The honeycomb core is shaped and then layed up with the resin impregnated fabrics which may be individually , fibreglass, Kevlar, carbon fibre or a matrix of all of them at once...depends on the application. The resins used call for by design certain cure rates and cure temperatures. The parts will be cured in an autoclave the draws out any air and compresses the fabric layers while they cure out. This can take 1/2 hour to several. result is an incredibly light and very strong product.
Airbus led the way with composites in primary structures during the development of the A310. All the tail feathers were composite application. Next they redesigned the A300 tail grouping as compared to its alloy predecessor and yielded a weight savings of about 347 lbs. Not much but it allowed for more PX
seats...more flight revenue. Airbus has also pioneered Aluminum lithium into their designs. This is a product Boeing rejected during the 777 development as it had inherent fracture characteristics during manufacture. While composites have amazing qualities they have draw backs including internal damage detection, composites are porous so the exterior topcoat must always maintain its protective integrity. Repainting these surfaces requires a different approach as they are easily damaged. They are also easily repaired. With the 787 as far as I am concerned the jury is open one this one. Not sure how fuselage damage repairs will be approached. Just because it is constructed of carbon fibre does not mean it is indestructible. The leading edges of the space shuttle Columbia were made from Carbon Carbon and we all saw what a block of lightweight foam did to it and the result that unfortunately followed. All in all, composites have made for intersting innovations in aircraft design...some good, some not.