De-couple geared turbo-fan engine and aircraft

1. An aircraft propulsion system comprising:

a core engine section mounted within an aft portion of an aircraft fuselage, the core engine section including a compressor section feeding air to a combustor to generate high speed exhaust gases that drive a turbine section all disposed about an engine axis;

a geartrain mounted within the aircraft fuselage and driven by the core engine section;

a fan section externally mounted to the aircraft fuselage and driven by the geartrain about a fan axis spaced apart from the engine axis; and

an accessory gearbox supported within the aircraft fuselage and driven by the geartrain and mounted apart from the core engine section and the fan section, the accessory gear box driving at least one system required for operation of the core engine section,

wherein the core engine section comprises a first core engine section disposed about a first axis and a second core engine section disposed about a second axis different than the first axis, the first core engine section and the second core engine section mounted within the aft portion of the aircraft fuselage and the fan section comprises first and second fan sections driven by a corresponding one of the first and second core engine sections.

2. The aircraft propulsion system as recited in claim 1 , including an inlet for supplying air to the core engine section mounted to the aircraft fuselage, the inlet defining a passageway supplying air separate from airflow through the fan section.

3. The aircraft propulsion system as recited in claim 1 , including a fan case surrounding the fan section, the fan case including a thrust reverser movable to a position directing thrust from the fan section in a direction to slow the aircraft.

4. The aircraft propulsion system as recited in claim 1 , including an exhaust nozzle disposed about the engine axis, the exhaust nozzle including a thrust reverser for directing exhaust gases from the core engine section in a direction to slow the aircraft.

5. The aircraft propulsion system as recited in claim 1 , including an input shaft driven by the core engine section for driving the geartrain, a first output shaft from the geartrain driving the fan section, and a second output shaft from the geartrain driving the accessory gearbox.

6. The aircraft propulsion system as recited in claim 1 , wherein the fan axis is parallel to the engine axis.

7. The aircraft propulsion system as recited in claim 1 , wherein the geartrain comprises first and second geartrains and the accessory gearbox comprises first and second accessory gearboxes driven by a corresponding one of the first and second geartrains.

8. An aircraft system comprising:

an elongated fuselage;

a wing structure extending from opposing sides of the fuselage;

a vertical stabilizer including a horizontal stabilizer surface mounted to an upper portion of the vertical stabilizer;

a first core engine section and a second core engine section mounted within an aft portion of an aircraft fuselage, each of the first core engine section and the second core engine section including a compressor section feeding air to a combustor to generate high speed exhaust gases that drive a turbine section disposed about an corresponding first engine axis and second engine axis;

a first geartrain and a second geartrain mounted within the aircraft fuselage and driven by a corresponding one of the first core section and the second core engine section;

a first fan section and a second fan section externally mounted to the aircraft fuselage and driven by a corresponding one of the first geartrain and the second geartrain about a corresponding one of a first fan axis and a second fan axis spaced apart from a corresponding one of the first engine axis and the second engine axis; and

an accessory gearbox supported within the aircraft fuselage and driven by at least one of the first geartrain and the second geartrain, the accessory gearbox mounted apart from the first core engine section, the second core engine section, the first fan section and the second fan section.

9. The aircraft system as recited in claim 8 , including an air inlet supplying air to each of the first and second core engine sections, the air inlet defining a passage supplying air separate of air flow through any of the first fan section and the second fan section.

10. The aircraft system as recited in claim 8 , wherein each of the first fan section and the second fan section are mounted above the wing structure.

11. The aircraft system as recited in claim 8 , wherein each of the first fan section and the second fan section comprise a bypass ratio greater than about 10.