  We argue the behavior of Poynting flux-dominated outflows from AGN in the
galactic cluster systems by performing three-dimensional MHD simulations within
the framework of the "magnetic tower" model. Of particular interests are the
structure of MHD waves, the cylindrical radial force balance, the
(de)collimation, and the stability properties of magnetic tower jets.
Transition between the jet/lobe and the formation of wiggling jet by growing
current-driven instability are discussed.
