Boeing this week completed the ultimate-load wing up-bending test on the 787 Dreamliner static test unit. It said initial results were positive, though "more extensive analysis and review are required before the test can be deemed a success."
During the testing, loads were applied to the airframe to replicate 150% of the most extreme forces the airplane is ever expected to experience in service, flexing the wings upward by approximately 25 feet (7.6 meters) during the test.
Engineers had decided in advance not to bend the wings to breaking point, as they did in 1995, bending the wings of a 777 until they broke in an explosive burst at 154% of the anticipated in-service maximum load, destroying the test plane, The Seattle Times reported. It quoted Boeing spokesperson Lorie Gunter as saying "There is no requirement to (do so) and the loads required are quite high, so we don't intend to expose our people or equipment when it is not necessary."
The test was conducted on one of two ground-test airplanes that will never fly, the Seattle Times said.
"The test program has been more robust than any conducted on a Boeing commercial jetliner," Vice President and General Manager of the 787 program, Boeing Commercial Airplanes Scott Fancher said. "It has taken countless hours of hard work by the Boeing team and our partners to work through the static test program. Everyone who has been involved in this effort over the past several years should be very proud of their contributions to ensuring the safety of the 787 Dreamliner."
During each second of the more than two-hour test, thousands of data points were collected to monitor the performance of the wing. Key data points were monitored real-time during the test, and the collected data will be evaluated in the coming weeks.
"We are looking forward to the technical team's report on the details of the test results," Fancher said. It will take them several weeks to work through all of the data.