A variable internal exhaust area nozzle for a gas turbine engine, comprising: a plurality of flap trains extending around a periphery of the gas turbine engine, with each flap train including a convergent flap pivotally attached to an engine body and a divergent flap pivotally attached to the engine body downstream of the convergent flap; and a fluid circuit in communication with the convergent and divergent flaps (108, 112) and configured to pivot the convergent and divergent flaps (108, 112) between a radially inward position and a radially outward position; wherein the convergent flap has a closing pressure chamber selectively communicating with a closing portion of the fluid circuit, and the convergent flap is configured to move radially outward in response to the closing pressure chamber receiving a working fluid from the closing portion of the fluid circuit; wherein the convergent flap has an opening pressure chamber selectively communicating with an opening portion of the fluid circuit, and the convergent flap is configured to move radially inward in response to the opening pressure chamber receiving a working fluid from the opening portion of the fluid circuit; characterized in that the divergent flap has a closing pressure chamber selectively communicating with a closing portion of the fluid circuit, and the divergent flap is configured to move radially outward in response to the closing pressure chamber receiving a working fluid from the closing portion of the fluid circuit; and wherein the divergent flap has an opening pressure chamber selectively communicating with an opening portion of the fluid circuit, and the divergent flap is configured to move radially inward in response to the opening pressure chamber receiving a working fluid from the opening portion of the fluid circuit. a plurality of flap trains extending around a periphery of the gas turbine engine, with each flap train including a convergent flap pivotally attached to an engine body and a divergent flap pivotally attached to the engine body downstream of the convergent flap; and a fluid circuit in communication with the convergent and divergent flaps (108, 112) and configured to pivot the convergent and divergent flaps (108, 112) between a radially inward position and a radially outward position; wherein the convergent flap has a closing pressure chamber selectively communicating with a closing portion of the fluid circuit, and the convergent flap is configured to move radially outward in response to the closing pressure chamber receiving a working fluid from the closing portion of the fluid circuit; wherein the convergent flap has an opening pressure chamber selectively communicating with an opening portion of the fluid circuit, and the convergent flap is configured to move radially inward in response to the opening pressure chamber receiving a working fluid from the opening portion of the fluid circuit; characterized in that the divergent flap has a closing pressure chamber selectively communicating with a closing portion of the fluid circuit, and the divergent flap is configured to move radially outward in response to the closing pressure chamber receiving a working fluid from the closing portion of the fluid circuit; and wherein the divergent flap has an opening pressure chamber selectively communicating with an opening portion of the fluid circuit, and the divergent flap is configured to move radially inward in response to the opening pressure chamber receiving a working fluid from the opening portion of the fluid circuit.