It’s not easy being a green airliner. The 787 Dreamliner–Boeing’s midsize, fuel-efficient passenger jet–is being delayed again.
The maiden flight of the 787–already two years overdue–was to take place on June 30, but today Boeing announced an indefinite delay to add more structural reinforcements.
“Consideration was given to a temporary solution that would allow us to fly as scheduled, but we ultimately concluded that the right thing was to develop, design, test and incorporate a permanent modification to the localized area requiring reinforcement,” Scott Carson, president and CEO of Boeing’s commercial-airplanes division, explained in a statement. “Structural modifications like these are not uncommon in the development of new airplanes, and this is not an issue related to our choice of materials or the assembly and installation work of our team.”
Carson’s mention of materials is important. The 787 is the first commercial aircraft in which major structural parts are made of composites rather than aluminum alloys. The difference slashes weight and helps boost the fuel efficiency of the plane by 20 percent. Back in 2003, we reported on this pioneering effort in commercial aviation.
Composite materials are notoriously difficult to model. Their fiber layers are oriented in different directions, and each layer is made of many individual fibers that vary somewhat in thickness. Such complex materials are far harder to precisely re-create in computer models, compared to monolithic chunks of aluminum. And Boeing has encountered trouble with 787 composites before. As we reported last spring, the company said that parts of the 787’s composite-made wing box–the major structural piece inside each wing, measuring more than 15 meters by 5 meters and weighing 55,000 pounds–had buckled in stress tests. To fix that problem, Boeing added new pieces and brackets and rerouted wiring to accommodate the retrofits.
The new schedule for the first flight–and the first delivery of some of the 865 787s that have been ordered by airlines–will not be available for several weeks, the company said.