An assembly for an aircraft propulsion system, comprising: a center body; a scarfed inlet structure extending circumferentially about the center body; and an inlet passage radially between and formed by at least the center body and the scarfed inlet structure, the inlet passage comprising a metering portion; a first component of the assembly configured to rotate about an axis relative to a second component of the assembly between: a first position where the metering portion has a first area; and a second position where the metering portion has a second area that is different than the first area; wherein the first component of the assembly comprises one of the center body or the scarfed inlet structure, and the second component of the assembly comprises the other one of the center body or the scarfed inlet structure; characterised in that: the center body includes a first tapered surface, a second tapered surface and a plateau surface that extends axially between the first tapered surface and the second tapered surface; the metering portion has an inner peripheral boundary; the inner peripheral boundary is formed by the plateau surface when the first component of the assembly is in the first position; the inner peripheral boundary is formed by the plateau surface and the second tapered surface when the first component of the assembly is in the second position; the plateau surface comprises a trailing edge; and a first point on the trailing edge is axially displaced from a second point on the trailing edge along the axis. a center body; a scarfed inlet structure extending circumferentially about the center body; and an inlet passage radially between and formed by at least the center body and the scarfed inlet structure, the inlet passage comprising a metering portion; a first component of the assembly configured to rotate about an axis relative to a second component of the assembly between: a first position where the metering portion has a first area; and a second position where the metering portion has a second area that is different than the first area; a first position where the metering portion has a first area; and a second position where the metering portion has a second area that is different than the first area; wherein the first component of the assembly comprises one of the center body or the scarfed inlet structure, and the second component of the assembly comprises the other one of the center body or the scarfed inlet structure; characterised in that: the center body includes a first tapered surface, a second tapered surface and a plateau surface that extends axially between the first tapered surface and the second tapered surface; the metering portion has an inner peripheral boundary; the inner peripheral boundary is formed by the plateau surface when the first component of the assembly is in the first position; the inner peripheral boundary is formed by the plateau surface and the second tapered surface when the first component of the assembly is in the second position; the plateau surface comprises a trailing edge; and a first point on the trailing edge is axially displaced from a second point on the trailing edge along the axis. the center body includes a first tapered surface, a second tapered surface and a plateau surface that extends axially between the first tapered surface and the second tapered surface; the metering portion has an inner peripheral boundary; the inner peripheral boundary is formed by the plateau surface when the first component of the assembly is in the first position; the inner peripheral boundary is formed by the plateau surface and the second tapered surface when the first component of the assembly is in the second position; the plateau surface comprises a trailing edge; and a first point on the trailing edge is axially displaced from a second point on the trailing edge along the axis.