A gas turbine engine, comprising: a high pressure compressor configured to provide a flow of air to an intershaft region between a first shaft and a second shaft concentric with the first shaft; a bearing compartment; a first air seal configured to seal between the first shaft and the bearing compartment; a first oil seal configured to seal between the first shaft and the bearing compartment; a second air seal configured to seal between the second shaft and the bearing compartment; a second oil seal configured to seal between the second shaft and the bearing compartment; and a buffer manifold in the intershaft region, characterised in that: a first portion (260, 262) of the flow of air from the high pressure compressor flows over the first and second air seals (230b, 230c), and a second portion of the flow of air from the high pressure compressor flows through the buffer manifold, the buffer manifold is fluidly coupled to a first tube and a second tube, the first tube fluidly coupled between the buffer manifold and a location between the first air seal and the first oil seal, and the second tube fluidly coupled between the buffer manifold and a location between the second air seal and the second oil seal, the buffer manifold includes an orifice plate having an orifice, the second portion of the flow of air from the high pressure compressor flows through the orifice, and inlets of the first and second tubes (250, 252) are downstream of the orifice plate; and the gas turbine engine further comprises a first plenum between the first air seal and the first oil seal, and a second plenum between the second air seal and the second oil seal, wherein the first tube is fluidly coupled to the first plenum and the second tube is fluidly coupled to the second plenum such that within the first plenum the air that has flowed over the first air seal is combined with the air from the first tube and the combined flow flows over the first oil seal, and such that within the second plenum the air that has flowed over the second air seal is combined with the air from the second tube and the combined flow flows over the second oil seal. a high pressure compressor configured to provide a flow of air to an intershaft region between a first shaft and a second shaft concentric with the first shaft; a bearing compartment; a first air seal configured to seal between the first shaft and the bearing compartment; a first oil seal configured to seal between the first shaft and the bearing compartment; a second air seal configured to seal between the second shaft and the bearing compartment; a second oil seal configured to seal between the second shaft and the bearing compartment; and a buffer manifold in the intershaft region, a first portion (260, 262) of the flow of air from the high pressure compressor flows over the first and second air seals (230b, 230c), and a second portion of the flow of air from the high pressure compressor flows through the buffer manifold, the buffer manifold is fluidly coupled to a first tube and a second tube, the first tube fluidly coupled between the buffer manifold and a location between the first air seal and the first oil seal, and the second tube fluidly coupled between the buffer manifold and a location between the second air seal and the second oil seal, the buffer manifold includes an orifice plate having an orifice, the second portion of the flow of air from the high pressure compressor flows through the orifice, and inlets of the first and second tubes (250, 252) are downstream of the orifice plate; and the gas turbine engine further comprises a first plenum between the first air seal and the first oil seal, and a second plenum between the second air seal and the second oil seal, wherein the first tube is fluidly coupled to the first plenum and the second tube is fluidly coupled to the second plenum such that within the first plenum the air that has flowed over the first air seal is combined with the air from the first tube and the combined flow flows over the first oil seal, and such that within the second plenum the air that has flowed over the second air seal is combined with the air from the second tube and the combined flow flows over the second oil seal.