A gas turbine engine comprising: a fan delivering air into a core path and into a bypass duct as bypass air, said air in said core path reaching a low pressure compressor, and then a high pressure compressor, air compressed by said high pressure compressor being delivered into a combustion section where it is mixed with fuel and ignited, products of the combustion passing downstream over a high pressure turbine and then a low pressure turbine, said low pressure turbine driving said low pressure compressor as a low speed spool, and a gear reduction being driven by said low speed spool to in turn drive said fan at a rate of speed lower than that of said low speed spool, said gear reduction being positioned inwardly of an inner core housing which defines an inner periphery of the core path, and; a splitter housing defining an outer periphery of the core path, a plurality of inlet stator vanes extending between said splitter and said inner core housing, and there being a flow area between adjacent stator vanes, wherein a hydraulic diameter is defined as: Hydraulic diameter = 4 × A / O + L + I + L, wherein A is the area between the leading edge of one vane, the leading edge of an adjacent vane, the inner periphery of the splitter, and the outer periphery of the inner core housing, L is the length of the leading edge of each vane, O is the length of the outer periphery of the vanes and I is the length of the inner periphery between adjacent vanes; characterised in that the plurality of inlet stator vanes are equally spaced about the entire circumference of the splitter housing, wherein the number and spacing of the plurality of vanes is such that the hydraulic diameter between each pair of spaced vanes is greater than or equal to about 3.8 cm (1.5 in). a fan delivering air into a core path and into a bypass duct as bypass air, said air in said core path reaching a low pressure compressor, and then a high pressure compressor, air compressed by said high pressure compressor being delivered into a combustion section where it is mixed with fuel and ignited, products of the combustion passing downstream over a high pressure turbine and then a low pressure turbine, said low pressure turbine driving said low pressure compressor as a low speed spool, and a gear reduction being driven by said low speed spool to in turn drive said fan at a rate of speed lower than that of said low speed spool, said gear reduction being positioned inwardly of an inner core housing which defines an inner periphery of the core path, and; a splitter housing defining an outer periphery of the core path, a plurality of inlet stator vanes extending between said splitter and said inner core housing, and there being a flow area between adjacent stator vanes, wherein a hydraulic diameter is defined as: Hydraulic diameter = 4 × A / O + L + I + L, wherein A is the area between the leading edge of one vane, the leading edge of an adjacent vane, the inner periphery of the splitter, and the outer periphery of the inner core housing, L is the length of the leading edge of each vane, O is the length of the outer periphery of the vanes and I is the length of the inner periphery between adjacent vanes; characterised in that the plurality of inlet stator vanes are equally spaced about the entire circumference of the splitter housing, wherein the number and spacing of the plurality of vanes is such that the hydraulic diameter between each pair of spaced vanes is greater than or equal to about 3.8 cm (1.5 in).