Northwest Orient Airlines Flight 710Thursday March 17, 1960
An in-flight separation of the wing. A design flaw caused an oscillation known as whirl mode to transfer propeller wobble to the outboard nacelles which induced flutter in the wing which led to the separation of the wing. Reduced stiffness of the structure and the entry of the aircraft into an area of severe clear air turbulence were contributing factors. One of two crashes with the same cause. See 9/29/59.