A cascade box , comprising: a plurality of lengthwise extending side turning vanes , each configured to have a side turning angle (β); and a plurality of forward turning vanes attached to respective adjacent ones of the plurality of side turning vanes , wherein each forward turning vane is configured to have a forward turning angle (α), and at least one of the forward turning vanes is configured to have a negative forward turning angle (α) such that said at least one forward turning vane is configured to redirect, in use, a bypass airflow in a direction having an axial component directed toward an aft portion of the cascade box , wherein: the cascade box is arranged to have a plurality of lengthwise columns, characterized in that each forward turning vane in a respective one of the lengthwise columns has the same said forward turning angle (α) as the other forward turning vanes in the respective lengthwise column; and the plurality of lengthwise extending columns includes a first column with all the forward turning vanes within the first column configured to have a first forward turning angle, and a second column with all the forward turning vanes within the second column configured to have a second forward turning angle, wherein the first forward turning angle is greater than the second forward turning angle. a plurality of lengthwise extending side turning vanes , each configured to have a side turning angle (β); and a plurality of forward turning vanes attached to respective adjacent ones of the plurality of side turning vanes , wherein each forward turning vane is configured to have a forward turning angle (α), and at least one of the forward turning vanes is configured to have a negative forward turning angle (α) such that said at least one forward turning vane is configured to redirect, in use, a bypass airflow in a direction having an axial component directed toward an aft portion of the cascade box , wherein: the cascade box is arranged to have a plurality of lengthwise columns, characterized in that each forward turning vane in a respective one of the lengthwise columns has the same said forward turning angle (α) as the other forward turning vanes in the respective lengthwise column; and the plurality of lengthwise extending columns includes a first column with all the forward turning vanes within the first column configured to have a first forward turning angle, and a second column with all the forward turning vanes within the second column configured to have a second forward turning angle, wherein the first forward turning angle is greater than the second forward turning angle. the cascade box is arranged to have a plurality of lengthwise columns, characterized in that each forward turning vane in a respective one of the lengthwise columns has the same said forward turning angle (α) as the other forward turning vanes in the respective lengthwise column; and the plurality of lengthwise extending columns includes a first column with all the forward turning vanes within the first column configured to have a first forward turning angle, and a second column with all the forward turning vanes within the second column configured to have a second forward turning angle, wherein the first forward turning angle is greater than the second forward turning angle. <EOS>