The aim of this project is to study novel positive approaches for replacement of the chromate content in primer paints on aerospace alloys. This is being carried out by a collaborative team involving partners in Ukraine, Russia, Hungary and Great Britain. The work described here reports on the study of synergisms, using mixtures of conventional inorganic inhibitors, on the inhibition of Al-Cu alloy 2024 (or Russian equivalent). The comparative inhibition of chromate and an ecologically safe pigment mixture was studied using electrochemical impedance spectroscopy (EIS) and X-ray photo-electron spectroscopy (XPS). Using this approach, a relatively high protective ability of a chromate-free combination of phosphate, calcium and zinc releasing pigments was observed as a function of time. Subsequent experiments demonstrated effective cathodic inhibition of copper-containing intermetallic precipitates. Finally, XPS showed that the protective film formed on the intermetallic surface mainly consists of a zinc substituted calcium phosphate.