A system associated with a gas turbine engine having a central longitudinal axis, comprising: a first shaft axially extended along the central longitudinal axis; a second shaft coaxial with the first shaft; a high pressure compressor section (19B; 228-2); a bearing compartment and at least one buffer passage; characterised in that the system further comprises: a first air seal that seals between the first shaft and the second shaft at a first axial location; a second air seal that seals between the first shaft and the second shaft at a second axial location, wherein the high pressure compressor section (19B; 228-2) provides air to the first air seal and the second air seal; and a meter connected to the buffer passage that exhausts a portion of the air; wherein the first air seal and the second air seal regulate a flow of air entering the buffer passage; the system further comprising: a third air seal that seals between the first shaft and the bearing compartment at a third axial location; a fourth air seal that seals between the second shaft and the bearing compartment at a fourth axial location, wherein the third air seal and the fourth air seal consume a portion of the air that is in the buffer passage; a first drain substantially located at the third axial location configured to exhaust at least a portion of air that enters the at least one buffer passage; and a second drain substantially located at the fourth axial location configured to exhaust at least a portion of air that enters the at least one buffer passage. a first shaft axially extended along the central longitudinal axis; a second shaft coaxial with the first shaft; a high pressure compressor section (19B; 228-2); a bearing compartment and at least one buffer passage; characterised in that the system further comprises: a first air seal that seals between the first shaft and the second shaft at a first axial location; a second air seal that seals between the first shaft and the second shaft at a second axial location, wherein the high pressure compressor section (19B; 228-2) provides air to the first air seal and the second air seal; and a meter connected to the buffer passage that exhausts a portion of the air; wherein the first air seal and the second air seal regulate a flow of air entering the buffer passage; the system further comprising: a third air seal that seals between the first shaft and the bearing compartment at a third axial location; a fourth air seal that seals between the second shaft and the bearing compartment at a fourth axial location, wherein the third air seal and the fourth air seal consume a portion of the air that is in the buffer passage; a first drain substantially located at the third axial location configured to exhaust at least a portion of air that enters the at least one buffer passage; and a second drain substantially located at the fourth axial location configured to exhaust at least a portion of air that enters the at least one buffer passage. a first air seal that seals between the first shaft and the second shaft at a first axial location; a second air seal that seals between the first shaft and the second shaft at a second axial location, wherein the high pressure compressor section (19B; 228-2) provides air to the first air seal and the second air seal; and a meter connected to the buffer passage that exhausts a portion of the air; wherein the first air seal and the second air seal regulate a flow of air entering the buffer passage; the system further comprising: a third air seal that seals between the first shaft and the bearing compartment at a third axial location; a fourth air seal that seals between the second shaft and the bearing compartment at a fourth axial location, wherein the third air seal and the fourth air seal consume a portion of the air that is in the buffer passage; a first drain substantially located at the third axial location configured to exhaust at least a portion of air that enters the at least one buffer passage; and a second drain substantially located at the fourth axial location configured to exhaust at least a portion of air that enters the at least one buffer passage. a third air seal that seals between the first shaft and the bearing compartment at a third axial location; a fourth air seal that seals between the second shaft and the bearing compartment at a fourth axial location, wherein the third air seal and the fourth air seal consume a portion of the air that is in the buffer passage; a first drain substantially located at the third axial location configured to exhaust at least a portion of air that enters the at least one buffer passage; and a second drain substantially located at the fourth axial location configured to exhaust at least a portion of air that enters the at least one buffer passage.