  We propose a lattice model for Dirac fermions which allows us to break the
degeneracy of the node structure. In the presence of a random gap we analyze
the scaling behavior of the localization length as a function of the system
width within a numerical transfer-matrix approach. Depending on the strength of
the randomness, there are different scaling regimes for weak, intermediate and
strong disorder. These regimes are separated by transitions that are
characterized by one-parameter scaling.
