A gas turbine engine for an aircraft comprising: an engine core comprising a turbine, a compressor, and a core shaft connecting the turbine to the compressor; a fan located upstream of the engine core, the fan comprising a plurality of fan blades; a bypass duct downstream of the fan; a bleed conduit arranged to receive bleed air from the compressor; and a louvre assembly comprising: an air discharge opening; a first louvre extending across a first portion of the air discharge opening and comprising a first plurality of slats each pivotably mounted to rotate about a first direction between a closed position to obstruct air flowing through the first portion of the air discharge opening and an open position to allow air to flow through the first portion of the air discharge opening; and a second louvre extending across a second portion of the air discharge opening and comprising a second plurality of slats each pivotably mounted to rotate about a second direction between a closed position to obstruct air flowing through the second portion of the air discharge opening and an open position to allow air to flow through the second portion of the air discharge opening, wherein the discharge opening is arranged to direct bleed air from the bleed conduit into the bypass duct with the first and second pluralities of slats in the open position, characterised in that the first and second directions (405, 409) are angled relative to each other such that air exiting through the air discharge opening with the first and second plurality of slats (404, 408) in the open position diverges away from a central axis of the louvre assembly extending between the first and second portions (403, 407) of the air discharge opening. an engine core comprising a turbine, a compressor, and a core shaft connecting the turbine to the compressor; a fan located upstream of the engine core, the fan comprising a plurality of fan blades; a bypass duct downstream of the fan; a bleed conduit arranged to receive bleed air from the compressor; and a louvre assembly comprising: an air discharge opening; a first louvre extending across a first portion of the air discharge opening and comprising a first plurality of slats each pivotably mounted to rotate about a first direction between a closed position to obstruct air flowing through the first portion of the air discharge opening and an open position to allow air to flow through the first portion of the air discharge opening; and a second louvre extending across a second portion of the air discharge opening and comprising a second plurality of slats each pivotably mounted to rotate about a second direction between a closed position to obstruct air flowing through the second portion of the air discharge opening and an open position to allow air to flow through the second portion of the air discharge opening, wherein the discharge opening is arranged to direct bleed air from the bleed conduit into the bypass duct with the first and second pluralities of slats in the open position, an air discharge opening; a first louvre extending across a first portion of the air discharge opening and comprising a first plurality of slats each pivotably mounted to rotate about a first direction between a closed position to obstruct air flowing through the first portion of the air discharge opening and an open position to allow air to flow through the first portion of the air discharge opening; and a second louvre extending across a second portion of the air discharge opening and comprising a second plurality of slats each pivotably mounted to rotate about a second direction between a closed position to obstruct air flowing through the second portion of the air discharge opening and an open position to allow air to flow through the second portion of the air discharge opening, wherein the discharge opening is arranged to direct bleed air from the bleed conduit into the bypass duct with the first and second pluralities of slats in the open position, characterised in that the first and second directions (405, 409) are angled relative to each other such that air exiting through the air discharge opening with the first and second plurality of slats (404, 408) in the open position diverges away from a central axis of the louvre assembly extending between the first and second portions (403, 407) of the air discharge opening.