During the operation of the rotor, the top coat of a blade, which is a thin film, may detach on some part of its length. To estimate the functionality of the construction, it is important to know the further scenario of the behavior of such a film with a detached fragment. Such defects may appear and grow for several reasons, which include wind loads and stationary oscillations arising in blades during their operation. We study the possibility of oscillation localization near delaminations from cracks and the impact of localization on the growth of the defects. We suggest a model for analyzing conditions under which a detachment zone grows or ceases to grow.