Low cost airfoil cooling circuit with sidewall impingement cooling chambers

A gas turbine engine airfoil includes an airfoil outer wall having widthwise spaced apart pressure and suction sidewall sections extending chordally between leading and trailing edges of the airfoil and extending longitudinally from a base to a tip. Inside the airfoil is at least one internal cooling circuit having a plurality of longitudinally extending circuit channels between longitudinally extending internal ribs extending widthwise between the pressure and suction sidewall sections and a longitudinally extending first sidewall film cooling chamber positioned between one of the sidewall sections and a first inner wall bounding the cooling circuit. Sidewall film cooling holes extend through the pressure sidewall section from the first sidewall film cooling chamber. The internal ribs have corresponding rib angles with respect to a centerline, the first inner wall has a corresponding first wall angle with respect to the centerline, and each of the rib angles and the first wall angle are constant in a longitudinal direction from the base to the tip. In the preferred embodiment, all the inner walls are substantially parallel to each other and all the transverse ribs are substantially parallel to each other or are substantially parallel to the first and second inner walls.