An airfoil (400; 500; 600) for a gas turbine engine, the airfoil comprising: a leading edge (402; 502), a trailing edge (404; 504), a pressure side exterior wall (406; 506; 606) extending between the leading edge and the trailing edge and defining a pressure side, and a suction side exterior wall (408; 508; 608) extending between the leading edge and the trailing edge and defining a suction side, wherein a plurality of cooling passages (410, 412, 414, 416, 418, 410; 516, 518; 616, 618) are formed within the airfoil; a plurality of first interior ribs extending from the pressure side exterior wall to the suction side exterior wall; and a plurality of second interior ribs extending from the suction side exterior wall toward the pressure side exterior wall and intersecting with one of the first interior ribs of the plurality of first interior ribs, wherein: at least one pressure side main body cooling passage (416; 516; 616) is defined between the pressure side exterior wall and two first interior ribs of the plurality of first interior ribs, at least one suction side main body cooling passage (418; 518; 618) is defined between the suction side exterior wall, a first interior rib, and a second interior rib; and at least one isolated main body cooling passage is defined between two first interior ribs and two second interior ribs, characterised in that the at least one isolated main body cooling passage is configured to supply cooling air to a tip of the airfoil; and the airfoil defines a camber line extending from the leading edge to the trailing edge, wherein the camber line is defined as a line that is equidistant from the pressure side and the suction side, wherein the camber line passes through each pressure side main body cooling passage. a leading edge (402; 502), a trailing edge (404; 504), a pressure side exterior wall (406; 506; 606) extending between the leading edge and the trailing edge and defining a pressure side, and a suction side exterior wall (408; 508; 608) extending between the leading edge and the trailing edge and defining a suction side, wherein a plurality of cooling passages (410, 412, 414, 416, 418, 410; 516, 518; 616, 618) are formed within the airfoil; a plurality of first interior ribs extending from the pressure side exterior wall to the suction side exterior wall; and a plurality of second interior ribs extending from the suction side exterior wall toward the pressure side exterior wall and intersecting with one of the first interior ribs of the plurality of first interior ribs, wherein: at least one pressure side main body cooling passage (416; 516; 616) is defined between the pressure side exterior wall and two first interior ribs of the plurality of first interior ribs, at least one suction side main body cooling passage (418; 518; 618) is defined between the suction side exterior wall, a first interior rib, and a second interior rib; and at least one isolated main body cooling passage is defined between two first interior ribs and two second interior ribs, characterised in that the at least one isolated main body cooling passage is configured to supply cooling air to a tip of the airfoil; and the airfoil defines a camber line extending from the leading edge to the trailing edge, wherein the camber line is defined as a line that is equidistant from the pressure side and the suction side, wherein the camber line passes through each pressure side main body cooling passage. at least one pressure side main body cooling passage (416; 516; 616) is defined between the pressure side exterior wall and two first interior ribs of the plurality of first interior ribs, at least one suction side main body cooling passage (418; 518; 618) is defined between the suction side exterior wall, a first interior rib, and a second interior rib; and at least one isolated main body cooling passage is defined between two first interior ribs and two second interior ribs, characterised in that the at least one isolated main body cooling passage is configured to supply cooling air to a tip of the airfoil; and the airfoil defines a camber line extending from the leading edge to the trailing edge, wherein the camber line is defined as a line that is equidistant from the pressure side and the suction side, wherein the camber line passes through each pressure side main body cooling passage.