A turbine blade for a gas turbine engine includes an airfoil including leading and trailing edges joined by spaced apart pressure and suction sides to provide an exterior airfoil surface extending in a radial direction. The trailing edge is arranged on an aft side of the turbine blade. A root supports a platform from which the airfoil extends and a cooling passage extends within the root in the radial direction to the airfoil. A lower wing is arranged beneath the platform on the aft side and extends in an axial direction to provide a U-shaped channel with the platform that extends in a circumferential direction. An impingement hole extends from the U-channel to the cooling passage.