An airfoil cooling system may be provided. An airfoil may have a pressure side and a suction side that are separated by a leading edge. The leading edge may pass through a stagnation point of the airfoil. A spar may have an outer surface comprising standoffs. The standoffs may define a cooling channel that extends across the leading edge on the outer surface of the spar, from the pressure side to the suction side. The cooling channel may have a first portion and a second portion defined by the standoffs. The first portion may be located closer to a base or a tip of the airfoil than the second portion. The spar may further comprise an inlet on the pressure side or the suction side. The inlet may be configured to convey a cooling fluid from a passageway located inside of the spar to the cooling channel.