Chapter 5 “Icy Incursion” – Frozen Shores, your primary target during the opening section should be to target everything that looks like a blue cylinder, or a vessel next to pipes marked by blue stripes, as well as the 2 dropships that appear at/after the second Oil Rig. Ignore the troopers and go for the indicated targets instead. The trophy should unlock during the brief conversation between Sev and Rico after passing the second Oil Rig. We recommend you do this on Recruit difficulty as there are no crosshairs when playing on Elite difficulty.
The above excerpt was extracted from "Killzone 3 Trophy Guide" at PS3Trophies.Org.