the vanes 8 can be mutually connected by an annular peripheral ring 9 the latter in the same way as the core 7 possibly being formed in a single piece with the vanes especially by molding from a plastic or from a magnesium based material fig2 partly shows the core 7 of the stator in projection in a radial direction as well as the flattened cross section of a guide vane 8 that is to say the flat closed curve obtained by cutting the vane through a cylindrical surface axisymmetric about the axis of the fan and by rolling this cylindrical surface out flat in the plane of the figure this flattened cross section features an aircraft wing profile the chord 10 of which is inclined by an acute angle u03c9 with respect to a radial plane such as that containing the downstream extremity 11 of the stator the invention provides for the angle u03c9 or angle of attack to lie between 25 and 35 u00b0 and for it to decrease progressively as the cross section moves away from the axis at least over the last 30 of the radial span of the vane fig2 also depicts the axial length l of the vane 8 which according to the invention advantageously lies between 40 and 60 mm also visible is the distance h max between the median line 12 of the profile.