A gas turbine engine having a principal rotational axis, the gas turbine engine comprising: a fan coaxial with the principal rotational axis; a nacelle circumferentially surrounding the fan; a core engine disposed downstream of the fan and extending along the principal rotational axis; a core engine casing circumferentially surrounding the core engine around the principal rotational axis, wherein the core engine casing extends along the principal rotational axis from a first casing end to a second casing end downstream of the first casing end, wherein the first casing end is proximal to the fan, and wherein the core engine casing comprises a casing outer surface; a bypass duct defined between the nacelle and the core engine casing; a plurality of diverter fences pivotally coupled to the core engine casing proximal to the first casing end, such that each diverter fence from the plurality of diverter fences is pivotable relative to the core engine casing about a pivot axis, wherein the plurality of diverter fences are arranged circumferentially around the principal rotational axis, wherein the pivot axis is circumferentially and obliquely inclined with respect to the principal rotational axis by a pivot inclination angle, and wherein each diverter fence comprises: a leading edge facing the first casing end and axially spaced apart from the first casing end along the principal rotational axis; a trailing edge opposite to the leading edge; an inboard edge extending between the leading edge and the trailing edge along the casing outer surface, wherein the inboard edge at least partially engages the casing outer surface; and an outboard edge opposite to the inboard edge and extending between the leading edge and the trailing edge; and an actuation mechanism operatively coupled to each diverter fence; wherein each diverter fence is configured to move between a first position in which the outboard edge is disposed adjacent to the casing outer surface and a second position in which the outboard edge is radially spaced apart from the casing outer surface, and wherein, in the second position, each diverter fence radially extends outwards from the casing outer surface into the bypass duct; and wherein the actuation mechanism is configured to selectively move each diverter fence between the first position and the second position. a fan coaxial with the principal rotational axis; a nacelle circumferentially surrounding the fan; a core engine disposed downstream of the fan and extending along the principal rotational axis; a core engine casing circumferentially surrounding the core engine around the principal rotational axis, wherein the core engine casing extends along the principal rotational axis from a first casing end to a second casing end downstream of the first casing end, wherein the first casing end is proximal to the fan, and wherein the core engine casing comprises a casing outer surface; a bypass duct defined between the nacelle and the core engine casing; a plurality of diverter fences pivotally coupled to the core engine casing proximal to the first casing end, such that each diverter fence from the plurality of diverter fences is pivotable relative to the core engine casing about a pivot axis, wherein the plurality of diverter fences are arranged circumferentially around the principal rotational axis, wherein the pivot axis is circumferentially and obliquely inclined with respect to the principal rotational axis by a pivot inclination angle, and wherein each diverter fence comprises: a leading edge facing the first casing end and axially spaced apart from the first casing end along the principal rotational axis; a trailing edge opposite to the leading edge; an inboard edge extending between the leading edge and the trailing edge along the casing outer surface, wherein the inboard edge at least partially engages the casing outer surface; and an outboard edge opposite to the inboard edge and extending between the leading edge and the trailing edge; and a leading edge facing the first casing end and axially spaced apart from the first casing end along the principal rotational axis; a trailing edge opposite to the leading edge; an inboard edge extending between the leading edge and the trailing edge along the casing outer surface, wherein the inboard edge at least partially engages the casing outer surface; and an outboard edge opposite to the inboard edge and extending between the leading edge and the trailing edge; and an actuation mechanism operatively coupled to each diverter fence; wherein each diverter fence is configured to move between a first position in which the outboard edge is disposed adjacent to the casing outer surface and a second position in which the outboard edge is radially spaced apart from the casing outer surface, and wherein, in the second position, each diverter fence radially extends outwards from the casing outer surface into the bypass duct; and wherein the actuation mechanism is configured to selectively move each diverter fence between the first position and the second position.