  We study a realization of a 1d chain of Majorana bound states at the
interfaces between alternating ferromagnetic and superconducting regions at a
quantum spin Hall insulator edge. In the limit of well separated Majoranas, the
system can be mapped to the transverse field Ising model. The disordered
critical point can be reached by tuning the relative magnitude or phases of the
ferromagnetic and superconducting order parameters. We compute the voltage
dependence of the tunneling current from a metallic tip into the Majorana chain
as a direct probe of the random critical state.
