Why Boeing 777X failed stress test

New images have surfaced of what really happened during the September pressure testing of Boeing’s new 777X aircraft. September’s pressure test was widely reported to have failed, with a cargo door being blamed for the issue.

Now, it seems that the situation was a lot more serious than that. According to reports, it wasn’t just the door that ruptured, but the entire fuselage!

Earlier reports that a cargo door blew out are not entirely unfounded. Apparently the fuselage skin ripped open just behind the wing, and as such a passenger door was dislodged and fell to the factory floor. The damage is clearly far worse than originally revealed; the test aircraft is a complete write-off.

Of the incident, Boeing spokesperson, Paul Bergmanm, explained that in the final load testing of the 777X static test airplane, the team conducted a test that involves bending the wings of the airplane up to a level far beyond anything expected in commercial service.

“A testing issue occurred during the final minutes of the test, at approximately 99 per cent of the final test loads, and involved a depressurisation of the aft fuselage. The test team followed all safety protocols.

“As we shared on our October 23 earnings call, our root cause assessment continues, and we are pleased with the progress we are making as we complete our detailed analysis. What we’ve seen to date reinforces our prior assessment that this will not have a significant impact on the design or our preparations for first flight. We do not see any impact from the test on the overall program schedule.

“On the call, we did update our target for first delivery from late 2020 to early 2021. As we’d said for some time, there had been significant risk to the late 2020 timeline. What changed is that we now have a clearer understanding of how the GE9X engine issue has impacted the details of our flight test program. For example, the timing of engines for the remaining flight test airplanes will affect when they begin flying, which in turn affects our detailed test schedules. When we account for all these factors, we expect to fly in early 2020 deliver in 2021.”