  The problem of vibration suppression in helicopter rotors is the main topic
of this paper. We revisit a strategy for the stabilization of such systems
based on delayed feedback. By means of an improved analysis, made possible by
recently developed mathematical tools, we present insights on how the delay can
be used as stabilization tool for this problem. The results are supported with
numerical simulations. For simplicity, only the case of hovering flight is
considered.
