A gas turbine engine (10) comprises a main fluid flow exhaust nozzle (30) bounding a main fluid flow path, and a cooling nozzle (38) provided upstream of the main fluid flow exhaust nozzle (30) in the main fluid flow path. The cooling nozzle (38) is arranged to provide cooling air to a surface (36) of the main fluid flow exhaust nozzle (30), the cooling nozzle (38) comprises first and second outlets (44, 46). The first outlet (44) is located adjacent the main fluid flow exhaust nozzle surface (36) and is spaced from the main fluid flow path by the second outlet (46). The second outlet (46) comprises a convergent divergent nozzle configured to accelerate cooling air exhausted from the second outlet (46) to a velocity greater than air exhausted from the first outlet (44).