Boeing says 787 meets targets

SEATTLE – Despite Boeing’s strenuous efforts to reduce the 787 Dreamliner’s weight, the plane weighed more than expected when it first rolled out two years ago.

And days before the new plane’s maiden flight last week, Boeing published a document for airlines that suggests to some weight-watching industry analysts that the 787 still exceeds its original target weight by a few tons.

Airlines have ordered 840 of the pioneering composite-plastic planes based on Boeing’s projections for its range, payload and fuel efficiency – all reduced by added weight.

In an interview, 787 chief project engineer Mike Delaney insisted the weight has been stable for the last two years.

And he said the Dreamliner will meet its targets for range and payload and still deliver on the original promise of being 20 percent more fuel efficient.

The 787 “is still meeting that commitment,” Delaney said.

Excess weight is a constant worry on any new airplane program. On the composite-plastic 787, the concern was amplified this year when Boeing discovered a structural flaw in the design and had to reinforce sections of the wing/body joint with titanium fittings.

One number Boeing won’t disclose is the basic weight of the empty plane – it never does during development. That fed speculation as the company made the modifications this fall.

“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,” Morgan Stanley financial analyst Heidi Wood wrote in an October research note.

Wood downgraded Boeing stock to the equivalent of a “sell,” citing concern about the weight of the airplane, among other issues.

Just before last week’s first flight, airlines received a briefing document that listed the maximum allowed takeoff weight of the jet as 9.25 tons heavier than in the version published two years ago.

Delaney said the document doesn’t mean many tons of weight have been added. Rather, he said, it describes the plane’s allowed operational weight, which Boeing has bumped up after its modeling and analysis showed the airplane structure to be strong enough to carry extra loads.

That means airlines can load the planes with more fuel and thereby meet payload and range requirements, despite the heaviness lingering from two years back.