A gas turbine engine comprising: an engine core comprising a compressor section (14, 15), a combustor downstream of the compressor section, and a turbine section (17, 18, 19) downstream of the combustor, the turbine section comprising at least one turbine blade row that is rotatable within a turbine casing; a tip clearance control system for directing air onto the turbine casing, the temperature of the air allowing a gap between the turbine blades and the turbine casing to be controlled; a fan upstream of the engine core, the fan being connected to at least a part of the turbine section so as to be driven in a fan rotation direction in use; a generally annular bypass duct located radially outside the engine core and being defined by a radially inner bypass duct wall and a radially outer bypass duct wall; and a bifurcation panel having first and second major surfaces that each extend from a leading edge to a trailing edge and generally radially across the bypass duct between the radially outer bypass duct wall and the radially inner bypass duct wall, wherein the bifurcation panel contains at least a part of an electrical and/or fluid system, thereby allowing the respective system to pass across the bypass duct; the tip clearance control system has a circumferentially extending manifold that extends around the turbine casing, the manifold being directly fluidly connected to at least one outlet positioned to provide air from the tip clearance control system to the turbine casing; the gas turbine engine being characterised in that: the direction that points through the bifurcation panel from the first major surface to the second major surface corresponds to the fan rotation direction; the tip clearance control system has an inlet positioned on the first major surface; and the inlet is closer to the trailing edge of the bifurcation panel than it is to the leading edge of the bifurcation panel. an engine core comprising a compressor section (14, 15), a combustor downstream of the compressor section, and a turbine section (17, 18, 19) downstream of the combustor, the turbine section comprising at least one turbine blade row that is rotatable within a turbine casing; a tip clearance control system for directing air onto the turbine casing, the temperature of the air allowing a gap between the turbine blades and the turbine casing to be controlled; a fan upstream of the engine core, the fan being connected to at least a part of the turbine section so as to be driven in a fan rotation direction in use; a generally annular bypass duct located radially outside the engine core and being defined by a radially inner bypass duct wall and a radially outer bypass duct wall; and a bifurcation panel having first and second major surfaces that each extend from a leading edge to a trailing edge and generally radially across the bypass duct between the radially outer bypass duct wall and the radially inner bypass duct wall, wherein the bifurcation panel contains at least a part of an electrical and/or fluid system, thereby allowing the respective system to pass across the bypass duct; the tip clearance control system has a circumferentially extending manifold that extends around the turbine casing, the manifold being directly fluidly connected to at least one outlet positioned to provide air from the tip clearance control system to the turbine casing; the gas turbine engine being characterised in that: the direction that points through the bifurcation panel from the first major surface to the second major surface corresponds to the fan rotation direction; the tip clearance control system has an inlet positioned on the first major surface; and the inlet is closer to the trailing edge of the bifurcation panel than it is to the leading edge of the bifurcation panel. the direction that points through the bifurcation panel from the first major surface to the second major surface corresponds to the fan rotation direction; the tip clearance control system has an inlet positioned on the first major surface; and the inlet is closer to the trailing edge of the bifurcation panel than it is to the leading edge of the bifurcation panel.