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 . <EOS>