Just an aside. When Boeing produced the B727 they tested one to destruction. The aircraft was in a hangar and very securely attached to the hangar floor, the tips of the wings were secured, by cables, to a winch in the roof and then slowly cranked up until the wings gave way, Just before the wings broke they were at a ridiculously high angle, well above the level of the fuselage, the bang, when they went, was heard all over the airfield!