Originally Posted by
India Four Two
CONSO,
Thanks for posting that 777 limit load test. Very impressive.
Do do you know how they held the fuselage down? Via the gear or straps?
I'm sure tdracer can get more detailed - but generally they use ' in broad terms straps' fore and aft of the wing box going around the fuselage and a ' strap' a bit forrward of the horizontal stabilizer area.
On the 767 program, when they ran the same test- as they go close to 150 percent limit load, the ' aft ' fuselage section twisted as in wringing a towel so the test was stopped. The result was that they had enough data to meet cert requirements. But they removed the plane and put it in the boneyard near the plant. A close look of the plane showed that that the ( rudder )( vert stabilizer skeleton was about 5 to 10 degrees from vertical. The reason was a manufacturing error which left out a circumferential ( hoop ) near the rear exit door.
generally, depending on data and percentage loads, going to full destruction is NOT a requiement. Boeing did not destroy the 787 wing because the required loads plus sa small margin was obtained- and taking it much further to break was simply NOT worthwhile. I'm sure a search boeing video or still will show just how much the 787 wijngs ere deflected up -it is spectacular