"In the final load testing of the 777X static test airplane, our team conducted a test that involves bending the wings of the airplane up to a level far beyond anything expected in commercial service", the Boeing statement said. "A testing issue occurred during the final minutes of the test, at approximately 99 percent of the final test loads, and involved a depressurization of the aft fuselage".
The Seattle Times reported on Wednesday that the fuselage of the 777X ripped during the test on the factory floor in September, causing a passenger door to blow out as well.
"The Seattle Times article is essentially accurate – no concerns here", Boeing Communications Director Charles Bickers said.
When Boeing's new 777X suffered a ground test failure in early September, it was not a cargo door blowout.— (((LG7))) (@Lechatbon) November 27, 2019
The 777X’s fuselage split dramatically during the September stress test.#Boeing777X #Boeinghttps://t.co/rhhv6wTEKW
The Boeing statement said the test team had followed all safety protocols.
Since the test, the company said it had rescheduled its target for the first delivery of the 777X to early 2021, from late 2020.
"As we’d said for some time, there had been a 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", the statement said.
Boeing has had a difficult year defending its safety record after investigations by US authorities into two crashes involving its 777 Max jet suggested the company was slow in acting on early information on risks involving the planes.