A fan for a gas turbine engine includes: an annular casing; a disk disposed inside the casing and mounted for rotation about an axial centerline, the disk including a row of fan blades extending radially outwardly therefrom; each of the fan blades including an airfoil having circumferentially opposite pressure and suction sides extending radially in span from a root to a tip, and extending axially in chord between spaced-apart leading and trailing edges, with the airfoils defining corresponding flow passages therebetween for pressurizing air; the row including no more than 21 and no less than 13 of the fan blades; and wherein each of the fan blades has a solidity defined by a ratio of the airfoil chord over a circumferential pitch of the fan blades, measured at 60% of a radial distance from the root to the tip, of less than about 1.6.

A fan rotor has a hub, and a plurality of axial flow fan blades extending radially outwardly of the hub. A radial compressor impeller is positioned radially inwardly of the fan blades. The radial compressor impeller has an upstream inlet which extends generally in an axial direction defined by an axis of rotation of the hub. The radial flow compressor impeller has an outlet that extends radially outwardly of the inlet, and into a supply passage for supplying air to a core engine. An engine is also disclosed.

A gas turbine engine includes a core engine defined about an axis, a gear system driven by the core engine, a fan, and a variable area flow system. The gear system defines a gear reduction ratio of greater than or equal to about 2.3. The fan is driven by the gear system about the axis to generate a bypass flow. The variable area flow system operates to effect the bypass flow.

A method of configuring a plurality of gas turbine engines includes the steps of configuring each of the engines with respective ones of a plurality of propulsors. Each propulsor includes a propulsor turbine and one of a fan and a propeller. Each of the engines is configured with respective ones of a plurality of substantially mutually alike gas generators, with the respective propulsor turbine driven by products of combustion downstream of the gas generator.

The described reduction gearbox of a gas turbine engine includes a first gear reduction stage having an input gear adapted to be driven by a turbine output shaft. The input gear transfers power received from the turbine output shaft laterally away from the input gear to an input speed gear. Each input speed gear engages an output speed gear to define a main speed reduction gear set, and the main speed reduction gear sets are laterally spaced apart from one another to define a gap. The gearbox has a second gear reduction stage driven by the output speed gears, the second stage adapted to drive an engine output shaft.

A gas turbine engine, including: low pressure spool having low pressure compressor and low pressure turbine connected by low pressure shaft; reduction gear train having sun gear, a carrier having a plurality of planet gears attached thereto, and a ring gear, wherein the sun gear, carrier or ring gear is connected to the low pressure shaft, and another of the sun gear, carrier and ring gear provides an output drive; a propulsive fan mounted fore of the gear train; a fan shafting arrangement comprising a fan shaft connected to the output drive of the gear train via a coupling, wherein the coupling includes a connection point to the fan shaft at a first end, and a connection point to the gear train at a second end wherein the first and second end are axial separated and radially separated and the axial separation is greater than the radial separation.

A gas turbine engine, including: a low pressure spool having a low pressure compressor and a low pressure turbine connected by a low pressure shaft; a reduction gear train having a sun gear, a carrier having a plurality of planet gears attached thereto, and a ring gear, wherein one of the sun gear, carrier or ring gear is connected to the low pressure shaft, and another of the sun gear, carrier and ring gear provides an output drive; a propulsive fan mounted fore of the gear train; a fan shafting arrangement comprising a fan shaft which is connected to the output drive of the gear train and a fan support shaft which passes through centre of the gear train along the axis of rotation of the gearbox and fan, wherein the fan shafting arrangement is rotatably supported by at least two axially separated bearings.