  We investigate the presence of percolating states in disordered
two-dimensional topological insulators. In particular, we uncover a close
connection between these states and the so-called topological Anderson
insulator (TAI), which is a topologically non-trivial phase induced by the
presence of disorder. The decay of this phase could previously be connected to
a delocalization of bulk states with increasing disorder strength. In this work
we identify this delocalization to be the result of a percolation transition of
states that circumnavigate the hills of the bulk disorder potential.
