Boeing must urgently address US rumors in the Seattle Post-Intelligencer and referenced on Jon Ostrower’s Flightblogger here that the wing on the static test 787 Dreamliner in Everett is delaminating.
The key weight saving feature of the 787 is the extensive use of reinforced sheets of carbon fibre bonded together with an epoxy resin and baked in a giant oven or autoclave. Delamination is another way of saying some of those sheets would be peeling apart. It will be ultra serious for the project if this rumor is true.
Carbon fibre reinforced plastics have been used in aircraft and yachts, and high performance racing cars for many decades. There are significant monolithic carbon fibre components in Boeing 777s and all of the current Airbus models. They are already widely used in vertical rudders and cabin floor structures. One Airbus A300-600R crashed killing all on board after the rudder and other components broke off when the aircraft was inadvertently overstressed by a pilot, and another older Airbus suffered serious rudder delamination blamed on the undetected corruption of the component by seepage.
The radical departure from existing use of carbon fibre based plastics in the Dreamliner is their deployment in the wings and load bearing shell of the fuselage. These parts of an airliner are designed to flex significantly during flight, and through the cycles of pressurization of the cabin. Boeing also devised a patented manufacturing process where the fuselage components are spun into place over a substructure called a mandril as layers of criss crossing carbon fibre tape are laid down to create a laminated cocoon that is designed to be lighter and stronger and pierced by fewer rivets or fasteners than the conventional aluminium alloy structures.
The rivets part of that equation has infamously proven to be troublesome on the 787. The incomplete and much delayed test aircraft are coming together way overweight. A valid question is whether any weight has been saved using plastic instead of tin. Considerable additional metal was added to the structure to ensure that the main body of the jet acted like a Faraday Cage to conduct lightning strikes through the structure with minimal damage.
Boeing is being asked to answer very straightforward questions. It is way past time for some really plain talking.