An air-cooled turbine rotor blade comprising: a platform and a tip, an outer surface extending radially outward from said platform and adapted to be cooled by a film of cooling air flowing thereover; a radial cooling air passage extending through the interior of said blade, which accommodates, when in use, a radially outward flow of cooling air; and a plurality of film cooling holes extending between said outer surface and said radial cooling passage, said plurality of film cooling holes being arranged in a row extending from adjacent said platform to adjacent said tip; characterized in that: each of said film cooling holes has a substantially constant cross-sectional area along the length thereof; and each of said film cooling holes in said row intersects said radial cooling passage such that said film cooling hole and that portion of said radial cooling passage immediately upstream from said intersection thereof with said film cooling hole in the direction of the cooling air flow through the radial cooling passage define an acute angle (α), whereby cooling air entering said film cooling hole from said radial cooling passage is angularly displaced greater than 90° from the flow of cooling air through said radial cooling passage for decreasing the momentum of airflow through said film cooling hole and any tendency of cooling air discharged from said film cooling hole at said outer airfoil surface to separate therefrom. a platform and a tip, an outer surface extending radially outward from said platform and adapted to be cooled by a film of cooling air flowing thereover; a radial cooling air passage extending through the interior of said blade, which accommodates, when in use, a radially outward flow of cooling air; and a plurality of film cooling holes extending between said outer surface and said radial cooling passage, said plurality of film cooling holes being arranged in a row extending from adjacent said platform to adjacent said tip; characterized in that: each of said film cooling holes has a substantially constant cross-sectional area along the length thereof; and each of said film cooling holes in said row intersects said radial cooling passage such that said film cooling hole and that portion of said radial cooling passage immediately upstream from said intersection thereof with said film cooling hole in the direction of the cooling air flow through the radial cooling passage define an acute angle (α), whereby cooling air entering said film cooling hole from said radial cooling passage is angularly displaced greater than 90° from the flow of cooling air through said radial cooling passage for decreasing the momentum of airflow through said film cooling hole and any tendency of cooling air discharged from said film cooling hole at said outer airfoil surface to separate therefrom. each of said film cooling holes has a substantially constant cross-sectional area along the length thereof; and each of said film cooling holes in said row intersects said radial cooling passage such that said film cooling hole and that portion of said radial cooling passage immediately upstream from said intersection thereof with said film cooling hole in the direction of the cooling air flow through the radial cooling passage define an acute angle (α), whereby cooling air entering said film cooling hole from said radial cooling passage is angularly displaced greater than 90° from the flow of cooling air through said radial cooling passage for decreasing the momentum of airflow through said film cooling hole and any tendency of cooling air discharged from said film cooling hole at said outer airfoil surface to separate therefrom.