S5 0836+710: An FRII jet disrupted by the growth of a helical instability? M. Perucho, I. Martí-Vidal, A. P. Lobanov and P. E. Hardee A&A, 545 (2012) A65 Published online: 05 September 2012 DOI: 10.1051/0004-6361/201219785