Boeing passed a major milestone today in the 787 Dreamliner program. Today's flight test of airframe ZA001, the first 787 to fly back in December, marks the end of flutter testing for the airplane.

The flutter test rig is used to induce flutter oscillation in aerofoil models in the two degrees of freedom pitch and yaw. To do this, a 2-D airfoil model is suspended elastically from a pitch spring ...