An airfoil array , comprising: an endwall ; and a plurality of airfoils radially projecting from the endwall , each airfoil having a first side and an opposite second side extending axially in chord between a leading edge and a trailing edge , the airfoils circumferentially spaced apart on the endwall thereby defining a plurality of flow passages between adjacent airfoils ; and a convex profiled region extending from the endwall adjacent the first side of at least one of said plurality of airfoils near the leading edge of the at least one of said plurality of airfoils to the second side of a neighboring airfoil , wherein the convex profiled region gradually increases in radial height to a local maximum in radial extent , characterised by further comprising: a concave profiled region in the endwall adjacent the first side between a range of about 30% to 80% of an axial chord of the airfoil having the first side and predominantly adjacent to the second side of the neighboring airfoil between a range of 0% to 100% of an axial chord of the airfoil having the second side and extending across said at least one of said plurality of flow passages , the concave profile region gradually decreases in radial height to a local minimum in radial extent , wherein the concave profiled region is elongated across the flow passage from the first side of at least one of said plurality of airfoils to the second side of an adjacent airfoil , and an extent of the concave profiled region adjacent the first side of the airfoil is less than an extent of the concave profiled region adjacent the second side of the adjacent airfoil . an endwall ; and a plurality of airfoils radially projecting from the endwall , each airfoil having a first side and an opposite second side extending axially in chord between a leading edge and a trailing edge , the airfoils circumferentially spaced apart on the endwall thereby defining a plurality of flow passages between adjacent airfoils ; and a convex profiled region extending from the endwall adjacent the first side of at least one of said plurality of airfoils near the leading edge of the at least one of said plurality of airfoils to the second side of a neighboring airfoil , wherein the convex profiled region gradually increases in radial height to a local maximum in radial extent , characterised by further comprising: a concave profiled region in the endwall adjacent the first side between a range of about 30% to 80% of an axial chord of the airfoil having the first side and predominantly adjacent to the second side of the neighboring airfoil between a range of 0% to 100% of an axial chord of the airfoil having the second side and extending across said at least one of said plurality of flow passages , the concave profile region gradually decreases in radial height to a local minimum in radial extent , wherein the concave profiled region is elongated across the flow passage from the first side of at least one of said plurality of airfoils to the second side of an adjacent airfoil , and an extent of the concave profiled region adjacent the first side of the airfoil is less than an extent of the concave profiled region adjacent the second side of the adjacent airfoil . <EOS>