An airfoil for a gas turbine engine comprising: an outer airfoil wall providing an exterior surface and multiple radially extending cooling passages (92,94,96,98;196,198), the exterior surface providing pressure and suctions sides joined by leading and trailing edges , the cooling passages including a supply passage (96;196) for a trailing edge cooling passage (98; 198), the supply passage (96; 196) being arranged upstream from in fluid communication with the trailing edge cooling passage (98;198), a cooling hole (124;224) extending through the outer airfoil wall from the supply passage (96;196) to the exterior surface on the suction side , wherein the cooling passages include first, second and third cooling passages (92,94,96;196) provided by first and second walls that extend internally between the outer airfoil wall and progressively aftward of one another, the supply passage provided by the third cooling passage (96;196), and wherein the first cooling passage includes a first baffle and the second cooling passage includes a second baffle , the first and second baffles including multiple cooling holes to provide impingement cooling on inner surfaces of the cooling passages (92,94,96;196), the cooling hole being arranged downstream from the second baffle ; and wherein the first baffle is spaced apart from the inner surface of the first cooling passage by a first rib , the second baffle is spaced apart from the inner surface of the second cooling passage by the second wall and a second rib , the third cooling passage (96;196) includes third ribs , and the first, second and third ribs are spaced apart from one another in a radial direction (R), permitting fluid flow in a chordwise direction (H); characterised in that : the radially extending first, second, third and trailing edge cooling passages (92,94,96,98;196,198) are fluidly connected to one another in the chordwise direction (H). an outer airfoil wall providing an exterior surface and multiple radially extending cooling passages (92,94,96,98;196,198), the exterior surface providing pressure and suctions sides joined by leading and trailing edges , the cooling passages including a supply passage (96;196) for a trailing edge cooling passage (98; 198), the supply passage (96; 196) being arranged upstream from in fluid communication with the trailing edge cooling passage (98;198), a cooling hole (124;224) extending through the outer airfoil wall from the supply passage (96;196) to the exterior surface on the suction side , wherein the cooling passages include first, second and third cooling passages (92,94,96;196) provided by first and second walls that extend internally between the outer airfoil wall and progressively aftward of one another, the supply passage provided by the third cooling passage (96;196), and wherein the first cooling passage includes a first baffle and the second cooling passage includes a second baffle , the first and second baffles including multiple cooling holes to provide impingement cooling on inner surfaces of the cooling passages (92,94,96;196), the cooling hole being arranged downstream from the second baffle ; and wherein the first baffle is spaced apart from the inner surface of the first cooling passage by a first rib , the second baffle is spaced apart from the inner surface of the second cooling passage by the second wall and a second rib , the third cooling passage (96;196) includes third ribs , and the first, second and third ribs are spaced apart from one another in a radial direction (R), permitting fluid flow in a chordwise direction (H); characterised in that : the radially extending first, second, third and trailing edge cooling passages (92,94,96,98;196,198) are fluidly connected to one another in the chordwise direction (H). <EOS>