  We report the observation of the twisted decay of quadruply charged vortices
in an atomic Bose-Einstein condensate. Supporting numerical simulations show
that the singly-charged vortices, which result from the decay of a
multi-charged vortex, twist around intertwined in the shape of helical Kelvin
waves. Finally, we propose to apply this effect to generate an almost isotropic
state of turbulence which we characterize in terms of the velocity statistics.
