Gas turbine engine bifurcation located fan variable area nozzle

A method of operating a turbofan gas turbine engine comprising the steps of:

• driving a fan connected to a first spool through a gear train, wherein the fan includes a plurality of fan blades, the first spool includes a first compressor and a fan drive turbine, a fan nacelle at least partially surrounds a core nacelle to define a bypass flow path and a variable fan nozzle exit area for bypass flow, the core nacelle houses the first spool and a second spool, the second spool includes a first turbine that drives a second compressor, and at least one bifurcation extends between the fan nacelle and the core nacelle in a radial direction and extends between a leading edge and a trailing edge in an axial direction with respect to an engine axis to support the core nacelle within the fan nacelle;
• varying a variable area flow system in communication with an internal flow passage through the at least one bifurcation to change a volume of the bypass flow through the at least one bifurcation and control the bypass flow through the variable fan nozzle exit area in response to a flight condition, wherein the variable area flow system is movable toward an open position to increase bypass flow through the variable fan nozzle exit area and toward a closed position to decrease bypass flow through the variable fan nozzle exit area;
• and
• wherein the variable area flow system includes a variable pylon intake and a variable pylon exhaust both established along the at least one bifurcation, the internal flow passage extends between the pylon intake and the pylon exhaust, and the pylon intake includes a plurality of turning vanes moveable in response to an actuator.