Compressor apparatus with bleed slot and supplemental flange

An example compressor bleed slot apparatus includes an annular compressor casing, a blade row mounted for rotation about a centerline axis inside the compressor casing, a bleed slot passing through the forward section of the compressor casing, wherein the bleed slot is bounded by inboard and outboard walls defined within the compressor casing, the bleed slot extending along a slot axis, at least a portion of the bleed slot lying within an axial extent of the blade row, an array of struts interconnecting the inboard and outboard walls, and an annular supplemental flange extending radially outward from the forward section of the compressor casing, wherein at least a portion of the supplemental flange is axially positioned within an axial extent of the bleed slot, wherein the supplemental flange includes a necked-down portion adjacent the forward section of the compressor casing, the necked-down portion positioned axially between an inlet of the bleed slot and an outlet of the bleed slot.