It now seems that this wan’t “a pressurization test” at all. I occurred during a wing-bending test, as part of which the fuselage was normally pressurized. At 99 percent of maximum test wing bend, the fuselage suddenly depressurized because an aft door blew off. And “blew off” probably is an exaggeration, since at first nobody seemed to know what caused the depressurization, so I wasn’t as though the door came off like a cork out of a champagne bottle. It probably “failed,” I’m guessing as a result of fuselage distortion caused by the extreme wing bending.