A gas turbine engine comprising: an annular coupling (12; 112) extending along a centerline (C) and having coupling teeth (34; 134) that extend axially rearward; an annular air seal attachment (10; 110) comprising an air seal at an axially rearward end (20; 120), and air seal attachment teeth (26; 126) at an axially forward end (18; 118) that extend axially forward to interlock with the coupling teeth (34; 134) such that the air seal attachment teeth (26; 126) and the coupling teeth (34; 134) alternate in a circumferential direction; characterised in that the gas turbine engine further comprises: coupling tabs (36; 136) extending radially inward from the coupling teeth (34; 134); and air seal attachment tabs (28; 128) extending radially inward from the air seal attachment teeth (26; 126) with the air seal attachment tabs (28; 128) being axially forward of the coupling tabs (36; 136); wherein the gas turbine engine further comprises a retaining ring (42; 142) radially inward from the coupling teeth (34; 134) and the air seal attachment teeth (26; 126), the retaining ring (42; 142) being axially forward of the coupling teeth (34; 134) and axially rearward of the air seal attachment teeth (26; 126) to prevent axial movement of the air seal attachment (10; 110) relative to a shaft (14; 114). an annular coupling (12; 112) extending along a centerline (C) and having coupling teeth (34; 134) that extend axially rearward; an annular air seal attachment (10; 110) comprising an air seal at an axially rearward end (20; 120), and air seal attachment teeth (26; 126) at an axially forward end (18; 118) that extend axially forward to interlock with the coupling teeth (34; 134) such that the air seal attachment teeth (26; 126) and the coupling teeth (34; 134) alternate in a circumferential direction; characterised in that the gas turbine engine further comprises: coupling tabs (36; 136) extending radially inward from the coupling teeth (34; 134); and air seal attachment tabs (28; 128) extending radially inward from the air seal attachment teeth (26; 126) with the air seal attachment tabs (28; 128) being axially forward of the coupling tabs (36; 136); wherein the gas turbine engine further comprises a retaining ring (42; 142) radially inward from the coupling teeth (34; 134) and the air seal attachment teeth (26; 126), the retaining ring (42; 142) being axially forward of the coupling teeth (34; 134) and axially rearward of the air seal attachment teeth (26; 126) to prevent axial movement of the air seal attachment (10; 110) relative to a shaft (14; 114). coupling tabs (36; 136) extending radially inward from the coupling teeth (34; 134); and air seal attachment tabs (28; 128) extending radially inward from the air seal attachment teeth (26; 126) with the air seal attachment tabs (28; 128) being axially forward of the coupling tabs (36; 136); wherein the gas turbine engine further comprises a retaining ring (42; 142) radially inward from the coupling teeth (34; 134) and the air seal attachment teeth (26; 126), the retaining ring (42; 142) being axially forward of the coupling teeth (34; 134) and axially rearward of the air seal attachment teeth (26; 126) to prevent axial movement of the air seal attachment (10; 110) relative to a shaft (14; 114). <EOS>