A two dimensional gas turbine engine exhaust nozzle comprising: transversely spaced apart upper and lower convergent and divergent flaps (54, 56; 58, 60) extending longitudinally in a downstream direction along a nozzle axis and disposed between two widthwise spaced apart sidewalls (70, 72), said upper and lower divergent flaps (58, 60) having inwardly facing upper and lower flap surfaces (74, 76) defining together with said sidewalls (70, 72) at least a part of an exhaust stream flowpath therebetween, said upper and lower flap surfaces (74, 76) having respective upper and lower apexes (84, 86) wherein said upper apex is axially spaced apart and aft of said lower apex, and said upper divergent flap having an expansion ramp diverging away from said nozzle axis, including a ramp section of said upper flap surface extending aftwardly from said upper apex and extending aftwardly of a trailing edge of said lower divergent flap; characterized in that: said nozzle further comprises transversely spaced apart upper and lower convergent and divergent flap axes (96, 98; 100, 102) extending widthwise between said sidewalls (70, 72), wherein said upper convergent and divergent flaps (54, 58) are rotatable about said upper convergent and divergent flap axes (96, 100) and said lower convergent and divergent flaps (56, 60) are rotatable about said lower convergent and divergent flap axes (98, 102) respectively. transversely spaced apart upper and lower convergent and divergent flaps (54, 56; 58, 60) extending longitudinally in a downstream direction along a nozzle axis and disposed between two widthwise spaced apart sidewalls (70, 72), said upper and lower divergent flaps (58, 60) having inwardly facing upper and lower flap surfaces (74, 76) defining together with said sidewalls (70, 72) at least a part of an exhaust stream flowpath therebetween, said upper and lower flap surfaces (74, 76) having respective upper and lower apexes (84, 86) wherein said upper apex is axially spaced apart and aft of said lower apex, and said upper divergent flap having an expansion ramp diverging away from said nozzle axis, including a ramp section of said upper flap surface extending aftwardly from said upper apex and extending aftwardly of a trailing edge of said lower divergent flap; characterized in that: said nozzle further comprises transversely spaced apart upper and lower convergent and divergent flap axes (96, 98; 100, 102) extending widthwise between said sidewalls (70, 72), wherein said upper convergent and divergent flaps (54, 58) are rotatable about said upper convergent and divergent flap axes (96, 100) and said lower convergent and divergent flaps (56, 60) are rotatable about said lower convergent and divergent flap axes (98, 102) respectively. said nozzle further comprises transversely spaced apart upper and lower convergent and divergent flap axes (96, 98; 100, 102) extending widthwise between said sidewalls (70, 72), wherein said upper convergent and divergent flaps (54, 58) are rotatable about said upper convergent and divergent flap axes (96, 100) and said lower convergent and divergent flaps (56, 60) are rotatable about said lower convergent and divergent flap axes (98, 102) respectively.