TURBOFAN ENGINE AND METHOD OF OPERATING SAME

An auxiliary duct (26) branches radially outwardly from the bypass duct (20), has a proximal end (30) fluidly connecting the bypass duct (20) and a distal end (32), a valve (36) is activatable to selectively open and close the auxiliary passage (34), and a structure (44) protrudes partially from the auxiliary duct (26) into the auxiliary passage (34). The structure (44) is spaced apart from the proximal end (30), between the proximal end (30) and the valve (36), the structure (44) generating lesser pressure losses when flow in the auxiliary passage (34) is directed towards the distal end (32) than when the flow is directed towards the proximal end (30).