A dual-wall airfoil for use in a gas turbine engine, the airfoil having a pressure side, a suction side, a leading edge, and a trailing edge, the airfoil comprising: a spar including a cooling air plenum disposed along an airfoil axis, the airfoi axis extending radially perpendicular to a central axis of the gas turbine engine, and further comprising an outer surface, a plurality of standoffs disposed along the pressure side of the airfoil, a leading edge wall disposed at the leading edge of the airfoil and extending away from the outer surface of the spar, and a leading separator wall extending away from the outer surface of the spar and spaced apart from the leading edge wall, the leading edge wall and the leading separator wall extending in a direction along the airfoil axis, the standoffs disposed spaced apart from another to define a plurality of grooves, the standoffs and the grooves extending in a direction transversing the leading separator wall, wherein the leading separator wall divides the grooves into a plurality of body section leading grooves and a plurality of body section trailing grooves, the body section leading grooves being closer in proximity to the leading edge than the plurality of body section trailing grooves, wherein a portion of the spar along one of the body section leading grooves defines an inlet port (30A, 30B, 30C, 30A', 30B') in communication with the cooling air plenum; and a cover sheet coupled to the leading edge wall and the standoffs over the body section leading grooves, the cover sheet comprising an outlet port at the leading edge of the airfoil that is in communication with the respective groove such that the outlet port is disposed downstream of the inlet port, wherein the inlet port (30A, 30B, 30C, 30A', 30B') is configured to deliver cooling air from the cooling air plenum to the cover sheet for impingement cooling at the cover sheet, and the outlet port is configured to allow the cooling air to exit the respective groove, and characterised in that ends of the standoffs are spaced from the leading edge wall to define an internal plenum that is in communication with the outlet port. a spar including a cooling air plenum disposed along an airfoil axis, the airfoi axis extending radially perpendicular to a central axis of the gas turbine engine, and further comprising an outer surface, a plurality of standoffs disposed along the pressure side of the airfoil, a leading edge wall disposed at the leading edge of the airfoil and extending away from the outer surface of the spar, and a leading separator wall extending away from the outer surface of the spar and spaced apart from the leading edge wall, the leading edge wall and the leading separator wall extending in a direction along the airfoil axis, the standoffs disposed spaced apart from another to define a plurality of grooves, the standoffs and the grooves extending in a direction transversing the leading separator wall, wherein the leading separator wall divides the grooves into a plurality of body section leading grooves and a plurality of body section trailing grooves, the body section leading grooves being closer in proximity to the leading edge than the plurality of body section trailing grooves, wherein a portion of the spar along one of the body section leading grooves defines an inlet port (30A, 30B, 30C, 30A', 30B') in communication with the cooling air plenum; and a cover sheet coupled to the leading edge wall and the standoffs over the body section leading grooves, the cover sheet comprising an outlet port at the leading edge of the airfoil that is in communication with the respective groove such that the outlet port is disposed downstream of the inlet port, wherein the inlet port (30A, 30B, 30C, 30A', 30B') is configured to deliver cooling air from the cooling air plenum to the cover sheet for impingement cooling at the cover sheet, and the outlet port is configured to allow the cooling air to exit the respective groove, and characterised in that ends of the standoffs are spaced from the leading edge wall to define an internal plenum that is in communication with the outlet port.