Previous treatments of fuel slosh coupling with aircraft dynamics are extended to the case in which fuel tanks are skewed to the direction of flight, as in swept wing tanks. General and linearized equations of motion are developed and example calculations are made based on the Boeing 747-100 airplane. Slosh appears to be possible for swept wings only over a limited pitch attitude range, dependent on wing dihedral. For the example airplane at landing approach attitudes, coupling cannot happen, because partial inboard main wing tank fuel is fixed by gravity at the inboard tank ends. The gravity fixity is removed for an assumed lower dihedral angle. Then, slosh coupling with the Dutch roll mode of motion is small, but an unstable real root develops, similar to the spiral mode. Fuel slosh coupling to the Dutch roll mode is even smaller for centerline (unskewed) tanks. Tank locations forward of the aircraft's center of gravity are destabilizing. [References: 8]
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