Boeing has released documents for airlines that show an increase in the 787 Dreamliner’s maximum allowable takeoff weight by 9.25 tons, sparking critics to speculate the number may account for increased girth as opposed to increased capacity. Boeing generally doesn’t disclose empty weights while its aircraft are still in development/testing, but that hasn’t stopped some analysts from speculating the worst and using that speculation to help drive down the price of Boeing stock. “The 787-8 appears to have evolved from a once-elegant composite design to one saddled with carbuncles of heavy titanium added throughout for strengthening,” wrote Morgan Stanley financial analyst Heidi Wood. The analyst then downgraded Boeing stock, according to the LA Times. That happened in spite of the 787’s chief project engineer Mike Delaney’s comments that the jet’s weight has been stable for about two years, that it will meet its range and payload targets, that it will deliver the promise of a 20% increase in fuel efficiency, and that it has increased its payload capacity due to confirmation of its structural strength.
The history of composites includes designers who incorporated the materials into experimental designs to find the promise of weight reduction overtaken by less-than-ideal construction techniques and less-than-ideal raw materials. Significant advances in both realms may now have more than made up the difference. It will matter for the Dreamliner. Boeing’s 787 accounts for about 50 percent of its weight in composite structure and the jet’s recent adventures in wing-joint strengthening have resulted in the addition of titanium fittings.
