The invention relates to a guide vane segment for an aircraft gas turbine, comprising at least a radially outer shroud and a radially inner shroud, which extend along a respective circular arc and together form a ring segment, wherein, in the radial direction, between the outer shroud and the inner shroud, a plurality of guide vanes are arranged next to one another in the peripheral direction (UR), the vanes being materially joined with the inner shroud and the outer shroud, in particular joined in one piece. At least two securing ribs are arranged next to one another are formed on the trailing end face for at least one guide vane, wherein an intermediate space delimited by the two securing ribs in the peripheral direction (UR) is formed, this space tapering from radially outside to radially inside.