An airfoil cooling arrangement (12), including: a leading edge chamber (54) configured to cool an interior surface (68) of an airfoil; and an impingement orifice (60) configured to direct an impingement jet (64) toward an impingement location (66) disposed on the interior surface and offset from a camber line (28) of the airfoil. The airfoil cooling arrangement is effective to guide post impingement cooling fluid along the interior surface, through a leading portion (76) of the leading edge chamber, and then back toward a trailing edge (22) of the airfoil in a helical motion (114). A stagnation region (104) is formed adjacent the interior surface and on a trailing edge side of the impingement location, and a relatively high static pressure associated therewith is effective to contribute to the helical motion (114) of the post impingement cooling fluid within the leading edge chamber.