[DavidSJ]

One would presume this is purely a function of the pressure differential between the cabin and environment, which they presumably controlled for.

[fastball]

Doesn't sound like it.

"Engineers had the plane pressurized and on the ground. They loaded it up well beyond capacity and bent its wings in an extreme manner..."

[DavidSJ]

I was responding to a question about the difference between being on the ground and in the air, not one about the many other differences between this test and real-world operation.