Last week the Seattle Times reported that the damage observed during a ground test of the Dreamliner happened very late in the test, more specifically:
Just beyond "ultimate load." That is defined as 50 percent higher than the in-service limit load and is the Federal Aviation Administration's test target.
That would've been just fine and dandy, except that it turns out that they were just a little bit off and the damage actually occurred "well below the load the wings must bear to be federally certified to carry passengers." Whoops.
The structural flaws are described as
Stresses at the ends of the long rods that stiffen the upper wing skin panels caused the fibrous layers of the composite plastic material to delaminate.
Those long rods lead to the joints of the wings which connect to the body of the plane which lead to a fuselage box where excess load is transferred—-who cares how everything is connected? "Delaminate" as in "to split into thin layers"! Somehow I'm not reassured by being told that the delamination of the wing skin "isn't likely to lead to catastrophic failure of the airplane," though obviously they're not changing the design because it's not an issue. What's that? They are? Ah, well. What's another delay when the plane is already two years late? [Seattle Times]