Airfoil having expanded wall portions to accommodate film cooling holes

An airfoil for a gas turbine engine, the airfoil including a wall having an outer surface having a pressure side, a suction side spaced from the pressure side to define a hollow core for flowing cooling fluid therethrough, and, further including a rib disposed between the pressure side and the suction side, the rib separating a forward cavity and an aft cavity, the rib including a front surface facing into the forward cavity and defining a surface plane, and a cooling hole, the cooling hole extending through the wall and including an inlet in the hollow core and an outlet in the outer surface of the wall, the cooling hole having a hole axis extending in a direction forming an angle .alpha. with a tangent to the outer surface adjacent to the outlet, the cooling hole having a length (L.sub.1), measured from the inlet to the outlet of the cooling hole, and diameter (D.sub.2), and wherein the wall has an expanded section immediately forward of and chordwise continuous with the rib the expanded section having a thickness (T.sub.e), measured along the hole axis, equal to the length (L.sub.1), wherein the cooling hole extends through said expanded section such that the inlet faces into the forward cavity and the outlet is aft of the surface plane such that the cooling hole passes through the surface plane.