A turbine airfoil including a structural support system formed from chordal ribs within an internal cooling system in the airfoil. The chordal ribs forming the structural support system may be positioned in a cooling fluid supply channel in the hollow airfoil that is positioned proximate to a trailing edge cooling channel. The trailing edge cooling channel may include a plurality of pin fins forming a pin fin bank extending between inner surfaces of the pressure side wall and suction side wall. The chordal ribs may protrude from an inner surface of the outer wall of the hollow airfoil and extend in a general chordwise direction from a mid-chord region of the hollow airfoil to the trailing edge and into the pin fin bank. The structural support system reduces stresses proximate to the pin fins in the pin fin bank closest to the mid-chord region of the airfoil.