During the ultimate load test, the wings are then pulled upward. To pass the test and be certified, the wings must bend without breaking until the load on them reaches at least 150 percent of the normally expected load.
…
Sometimes this final test is continued beyond the 150 percent load target until a wing actually breaks. But not always.
…
This time, however, though the wings did not give way; it was one of the doors that failed — an outcome that is definitely not supposed to happen.
The cargo hatch blew open and the cabin floor collapsed on account of differential pressure, disabling the rudder, elevator and rear engine controls.
This may well not happen on a 777X -- various other airplanes have lost part of their cabin structure without crashing -- but an unexpected event calls into doubt your design.
Semantics.
https://www.seattletimes.com/business/boeing-aerospace/door-...
The Seattle Times explains it thusly:
During the ultimate load test, the wings are then pulled upward. To pass the test and be certified, the wings must bend without breaking until the load on them reaches at least 150 percent of the normally expected load.
…
Sometimes this final test is continued beyond the 150 percent load target until a wing actually breaks. But not always.
…
This time, however, though the wings did not give way; it was one of the doors that failed — an outcome that is definitely not supposed to happen.